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losing connection after fully charge!

Moe_BAT
Prodigy 10 points
Other Parts Discussed in Thread: BQ78350-R1, BQSTUDIO, BQ78350, EV2400

Hello everybody 

im fairly new to the forum and working with battery management.

Im using bq78350-R1 with bq7694.

1E9B_1_03-bq78350_R1 on bq Studio. 

 I have a 13SP4 battery pack. when i fully charge my battery pack i see the COV regsiter is set and i lose my connection on bqstudio until i discharge the battery for a few seconds and COV register is gone. 

In addtion, when connection to load the batteries never reach the CUV value i set as can be seen in the gg file attached. 

Can somebody help understanding this issue?

Thanks in advance.

Bq78350_R1_bq.gg.csv

  • 0
    TI__Guru* 79143 points

    Hi Mohammed,

    Are you using a TI Evaluation board or is this your own hardware? You may be losing communication when the protection FET is disabled. See this thread for more explanation: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1008592/bq78350-r1-smbd-smbc-line-voltage-in-case-of-lowsidefet-protection-being-open

    I am not sure I understand the description of your second issue. Does the battery stop discharging? If so, I suggest collecting a log file in BQStudio (click 'Start Log' in the Registers screen) - this will log all of the status registers to help determine what is happening.

    Regards,

    Matt

  • 0 in reply to Matt Sunna
    Prodigy 10 points

    Hello Matt

    Thanks for the reply. Im not using a TI Evaluation board. Its rather product hardware using the chips . I'll have to further investigate the board. the link helped alot.  here's a screen shot of the bq studio showing the problem. 

    Regarding my second point, sorry for the ambiguity. Yes battery stops discharging before reaching the value set by me for CUV. 

    I have attached two log files. one for discharge to show the problem meantioned above and another for a partial charge.and it seems I have encountered another problem with the communication I see a lot of errors due to commuincation problem as i see in the bq studio no acknowldgement from device. the error doesn't seem to appear in battery rest condition (no charge, no discharge) im using EV2400 by the way. 

    many thanks for the help 

    Regards

    Mohammed 

    4380.charge.log3632.discharge.log

  • 0 in reply to Moe_BAT
    TI__Guru* 79143 points

    Hi Mohammed,

    For the second point, I cannot see a reason for the discharge to stop - it does not look like the protection FETs are being opened by the BQ78350. Is there something else in your system that halts discharging if the SOC reports 0%? Because it is shortly after this point that the discharge stops.

    Regards,

    Matt

  • 0 in reply to Matt Sunna
    Prodigy 10 points

    Hello Matt,

    I confirm the first issue is resolved thank you for your support. 

    For the discharge problem i used a new board and the problem doesn't show anymore. However the communication problem is still there.

    my smb configuration as follows two bits are set fixed address (0x17) and  BLT1. i can confirm that smbc and smbd are pulled up with 3,1V and REGEOUT at 2,5V. 

    bq Studio keep showing me these error messages

    - no acknowledge from device.

    - Timeout or unexpected response communicating with device.

    - Packet checksum mismatch.

    i read somehwere in the forum that communication between gas gauge and AFE takes priorty to smb bus action. could you please elaborate more on this issue or would you happen to know what sort of problem could cause this? 

    Regards

    Mohammed

  • 0 in reply to Moe_BAT
    TI__Guru* 79143 points

    Hi Mohammed,

    Are the FETs enabled when the communication problems are occurring? I don't think the issues you are seeing are related to the gas gauge to AFE communication taking priority. This comes into play if you are constantly pinging the SMBus.

    Matt

  • 0 in reply to Matt Sunna
    Prodigy 10 points

    Hi Matt,

    Yes they're enabled when the problems are occurring as can be seen in the picture. i have attached a sample log file and error log file.

    3312.sample.log 
    Tue Jul 26 08:05:12 CEST 2022

Device Version Info = 1e9b_1_03
BQZ Device Name = bq78350_R1
BQZ Firmware Version = V1_03_BLD22

Design Capacity = 11600
Design Voltage = 3600
Specification Info = 0x0031
Manufacturer Date = 2022-6-9
Serial Number = 0x0001
Manufacturer Name = UNICAD
Device Name = 13S11.6AH
Device Chemistry = LION

Sample,DateTime,ElapsedTime,ManufAccess,RemCapAlarm,RemTimeAlarm,BattMode,@Rate(@),@TimeFull,@TimeEmpty,@RateOK,Temperature,Voltage,Current,AvgCurr,MaxErr,RSOC,ASOC,RemCap,FullChgCap,RunTimeEmty,RunTimeEmty,AvgTimeFull,ChgCurr,ChgVolt,BattStat,CycleCnt,PendingEdv,SoH,OpStatA,OpStatB,TempRange,ChgStat,GaugeStat,MfgStat,SafetyAlertAB,SafetyStatAB,SafetyAlertCD,SafetyStatCD,PFAlertAB,PFStatAB,PFStatAB,CellVolt1,CellVolt2,CellVolt3,CellVolt4,CellVolt5,CellVolt6,CellVolt7,CellVolt8,CellVolt9,CellVolt10,CellVolt11,CellVolt12,CellVolt13,CellVolt14,CellVolt15,ExtAvgCellVolt,TS1 Temp,TS2 Temp,TS3 Temp,CellTemp,FetTemp,GaugeInternalTemp,LogRowTime(ms),LogStatus
1,2022-07-26 08:05:16,4.001,0x0701,1160,10,0x6001,0,65535,65535,1,27.2,53585,973,976,100,95,94,10796,11415,65535,65535,62,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4134,4122,4117,4114,4126,4139,4101,4119,4120,4117,4102,4130,4144,0,0,4184,27.2,25.9,26.0,27.2,-273.2,38.3,960,SUCCESS
2,2022-07-26 08:05:20,8.002,0x0701,1160,10,0x6001,0,65535,65535,1,27.2,53586,973,976,100,95,94,10797,11415,65535,65535,62,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4134,4123,4117,4114,4126,4139,4101,4119,4120,4117,4102,4131,4144,0,0,4184,27.2,25.9,26.0,27.2,-273.2,38.2,952,SUCCESS
3,2022-07-26 08:05:24,12.002,0x0701,1160,10,0x6001,0,65535,65535,1,27.2,53588,978,976,100,95,94,10798,11415,65535,,,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4134,4123,4117,4114,4126,4139,4102,4120,4120,4117,4102,4130,4144,0,0,4184,27.2,25.9,26.0,27.2,-273.2,38.2,1006,ERROR : Please check C:\Users\Desktop\sample.log.err
4,2022-07-26 08:05:28,16.003,,1160,10,0x6001,0,65535,65535,1,27.2,53589,973,976,100,95,94,10800,11415,65535,65535,61,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,,4123,4117,4114,4126,4140,4101,4119,4120,4117,4102,4130,4144,0,0,4184,27.2,25.9,26.0,27.2,-273.2,38.2,1004,ERROR : Please check C:\Users\Desktop\sample.log.err
5,2022-07-26 08:05:32,20.003,0x0701,1160,10,0x6001,0,65535,65535,1,27.2,53591,973,977,100,95,94,10801,11415,65535,65535,61,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4123,4118,4114,4126,4140,4102,4120,4121,4117,4102,4130,4144,0,0,4184,27.2,25.9,26.1,27.2,-273.2,38.2,949,SUCCESS
6,2022-07-26 08:05:36,24.003,0x0701,1160,10,0x6001,0,65535,65535,1,27.2,53594,978,977,100,95,94,10802,11415,65535,65535,61,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4123,4118,4115,4126,4140,4102,4120,4121,4117,4102,4131,4145,0,0,4184,27.2,25.9,26.0,27.2,-273.2,38.1,947,SUCCESS
7,2022-07-26 08:05:40,28.004,0x0701,1160,10,0x6001,0,65535,65535,1,27.2,53594,978,977,100,95,94,10803,11415,65535,65535,61,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4123,4118,4115,4127,4140,4102,4120,4121,4118,4102,4131,4145,0,0,4184,27.2,25.9,26.1,27.2,-273.2,38.1,945,SUCCESS
8,2022-07-26 08:05:44,32.005,0x0701,1160,10,0x6001,0,65535,65535,1,27.2,53598,978,977,100,95,94,10804,11415,65535,65535,61,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4123,4118,4115,4127,4140,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.2,25.9,26.1,27.2,-273.2,38.1,942,SUCCESS
9,2022-07-26 08:05:48,36.005,0x0701,1160,10,0x6001,0,65535,65535,1,27.2,53600,982,977,100,95,94,10805,11415,65535,65535,61,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4115,4127,4141,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,25.9,26.1,27.1,-273.2,38.0,981,SUCCESS
10,2022-07-26 08:05:52,40.005,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53600,978,978,100,95,94,10806,11415,65535,65535,61,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4123,4118,4115,4127,4141,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,26.0,26.1,27.1,-273.2,38.0,959,SUCCESS
11,2022-07-26 08:05:56,44.006,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53600,978,978,100,95,94,10807,11415,65535,65535,61,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4115,4127,4141,4102,4120,4121,4117,4102,4131,4145,0,0,4184,27.1,26.0,26.2,27.1,-273.2,38.0,1006,ERROR : Please check C:\Users\Desktop\sample.log.err
12,2022-07-26 08:06:00,48.006,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53599,978,978,100,95,94,10808,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4115,4127,4141,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,26.0,26.2,27.1,-273.2,38.0,959,SUCCESS
13,2022-07-26 08:06:04,52.006,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53601,982,979,100,95,94,10809,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4115,4127,4141,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,26.0,26.1,27.1,-273.2,37.9,960,SUCCESS
14,2022-07-26 08:06:08,56.007,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53601,982,979,100,95,94,10810,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4116,4127,4141,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,26.0,26.1,27.1,-273.2,37.9,957,SUCCESS
15,2022-07-26 08:06:12,60.008,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53602,978,979,100,95,94,10812,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4116,4127,4141,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,26.0,26.2,27.1,-273.2,37.9,954,SUCCESS
16,2022-07-26 08:06:16,64.008,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53602,978,979,100,95,94,10813,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4116,4127,4142,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,26.0,26.1,27.1,-273.2,37.9,959,SUCCESS
17,2022-07-26 08:06:20,68.009,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53604,978,978,100,95,94,10814,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4124,4118,4116,4128,4142,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,26.0,26.1,27.1,-273.2,37.8,957,SUCCESS
18,2022-07-26 08:06:24,72.009,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53603,982,978,100,95,94,10815,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4116,4128,4142,4102,4120,4121,4118,4103,4131,4145,0,0,4184,27.1,25.9,26.1,27.1,-273.2,37.8,957,SUCCESS
19,2022-07-26 08:06:28,76.010,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53606,978,978,100,95,94,10816,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4135,4124,4118,4116,4128,4142,,4121,4122,4118,4103,4131,4145,0,0,4184,27.1,25.9,26.2,27.1,-273.2,37.8,986,ERROR : Please check C:\Users\Desktop\sample.log.err
20,2022-07-26 08:06:32,80.011,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53610,973,978,100,95,94,10817,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4124,4118,4116,4128,4142,4103,4121,4122,4119,4103,4132,4146,0,0,4184,27.1,25.9,26.1,27.1,-273.2,37.7,957,SUCCESS
21,2022-07-26 08:06:36,84.012,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53613,978,978,100,95,94,10818,11415,65535,65535,60,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4124,4119,4116,4128,4142,4103,4121,4122,4119,4103,4132,4145,0,0,4184,27.1,25.9,26.2,27.1,-273.2,37.7,951,SUCCESS
22,2022-07-26 08:06:40,88.012,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53614,978,978,100,95,94,10819,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4124,4119,4116,4128,4143,4103,4121,4122,4119,4103,4132,4146,0,0,4184,27.1,26.0,26.2,27.1,-273.2,37.7,953,SUCCESS
23,2022-07-26 08:06:44,92.013,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53613,978,978,100,95,94,10820,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4125,4119,4117,4129,4143,4103,4121,4122,4118,4103,4132,4146,0,0,4184,27.1,26.0,26.2,27.1,-273.2,37.7,950,SUCCESS
24,2022-07-26 08:06:48,96.013,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53616,982,979,100,95,94,10821,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4125,4119,4117,4129,4143,4103,4121,4122,4119,4104,4132,4146,0,0,4184,27.1,26.0,26.2,27.1,-273.2,37.6,955,SUCCESS
25,2022-07-26 08:06:52,100.014,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53614,973,979,100,95,94,10822,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4125,4119,4117,4129,4143,4103,4121,4122,4119,4103,4132,4146,0,0,4184,27.1,26.0,26.2,27.1,-273.2,37.6,949,SUCCESS
26,2022-07-26 08:06:56,104.015,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53616,978,979,100,95,94,10824,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4125,4119,4117,4129,4144,4103,4121,4122,4119,4104,4132,4146,0,0,4184,27.1,26.0,26.2,27.1,-273.2,37.6,949,SUCCESS
27,2022-07-26 08:07:00,108.015,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53617,978,979,100,95,94,10825,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4125,4119,4117,4129,4144,4103,4121,4122,4119,4104,4132,4146,0,0,4184,27.1,26.0,26.2,27.1,-273.2,37.6,946,SUCCESS
28,2022-07-26 08:07:04,112.016,0x0701,1160,10,0x6001,0,65535,65535,1,27.1,53619,973,979,100,95,94,10826,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4125,4119,4118,4129,4144,4103,4121,4122,4119,4104,4132,4146,0,0,4185,27.1,26.0,26.2,27.1,-273.2,37.6,945,SUCCESS
29,2022-07-26 08:07:08,116.016,0x0701,1160,10,0x6001,0,65535,65535,1,27.0,53618,978,978,100,95,94,10827,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4125,4119,4118,4129,4144,4103,4121,4122,4119,4104,4132,4146,0,0,4185,27.0,25.9,26.2,27.0,-273.2,37.6,952,SUCCESS
30,2022-07-26 08:07:12,120.017,0x0701,1160,10,0x6001,0,65535,65535,1,27.0,53621,978,977,100,95,94,10828,11415,65535,65535,59,1100,54600,0x0080,7,2750,98,0x0107,0x0002,0x04,0x02,0x10,0x02B0,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,4136,4125,4119,4118,4129,4144,4103,4121,4122,4120,4104,4133,4147,0,0,4184,27.0,25.9,26.2,27.0,-273.2,37.5,950,SUCCESS
    0407.sample.log.err.log 
    Tue Jul 26 08:05:24 CEST 2022

Time,LogCaption,Error Code,Error String
2022-07-26 08:05:24,RunTimeEmty,6,Timeout or unexpected response communicating with device.2022-07-26 08:05:24,AvgTimeFull,772,No acknowledge from device.2022-07-26 08:05:28,ManufAccess,6,Timeout or unexpected response communicating with device.2022-07-26 08:05:29,CellVolt1,6,Timeout or unexpected response communicating with device.2022-07-26 08:05:56,SafetyAlertAB,3,Packet checksum mismatch.2022-07-26 08:06:29,CellVolt7,6,Timeout or unexpected response communicating with device.

    Regards,

    Mohammed 

  • 0 in reply to Moe_BAT
    TI__Guru* 79143 points

    Hi Mohammed,

    A couple suggestions to see if it helps:

    • Uncheck the Scan button. This constantly communicates with the device reading the registers. If you have this button checked while you are collecting a log file, it may be too much traffic on the bus.
    • Try updating the EV2400 firmware to a newer version (0.32 is the latest). This may help with stability. Instructions for this are here: https://www.ti.com/tool/EV2400
    • Try unchecking the 'Log' box next to parameters that you are not using (like Cell 14 Voltage, Cell 15 Voltage, FET Temperature, PF Alert, PF Status, At Rate parameters, etc). This will reduce the amount of SMBus traffic.

    Regards,

    Matt

  • 0 in reply to Matt Sunna
    Prodigy 10 points

    Hi Matt,

    i uncheck the scan and refresh button on every log i take. 

    I took your advice with the update but problem still remains.

    Im trying to run the CEDV discharge logs and i only check for Voltage, Current, and Temperature. but errors still appear in the log. 

    Please let me know if i need to provide anything that could help solve the issue. 

    Regards,

    Mohammed 

  • 0 in reply to Moe_BAT
    TI__Guru* 79143 points

    Hi Mohammed,

    In this case, maybe something is wrong with the SMBus communication path. Can you capture the clock and data with a scope to see if the waveforms look okay? Do you have SMBus pullup resistors on your board, and if so which voltage rail are they using? The EV2400 has internal resistors pulling these lines to 3.3V.

    Regards,

    Matt

  • 0 in reply to Matt Sunna
    Prodigy 10 points

    Hi Matt,

    No SMBus pullup resistors in my board. EV2400 is pulling up the lines. 

    Please find the capture of the SMBus lines, i started taking the capture right before launching bq studio. I see 0xFF NAK spamming the data line every now and then. not sure why. I'd like to get your input on what your seeing.  

    PS. Capture was done with Salea logic analyzer.there's a free software to view the file thought it's worth mentioning, . 

    Many Thanks for your help,

    Regards,

    Mohammed  

     SMBus.zip 

  • 0 in reply to Moe_BAT
    TI__Genius 11315 points

    Hey Mohammed, 

    Since you have already lowered traffic on the communication lines and are still seeing issues, I do think Matt is right in saying that something may be wrong with the SMBus communication path. I would double check your layout. Also, is it possible for you to switch over to I2C and see if you are getting the same errors? 

    Thanks,
    Caleb

  • 0 in reply to Caleb Perez
    Prodigy 10 points

    Hi Caleb,

    Switching to I2C makes bq Studio not able to find the device. I'll have another look at the layout of the PCB though that's being done by manually checking the conncetions since layout isn't available. Can somebody take a look at the capture please and give me his thoughts. I also would like to mention that SMBus is referenced to Batt-. while the connection to bq studio is with P-. switching it to Batt- can make bq studio not able to identify the device. unless its in charging state. 

    Regards,

    Mohammed 

  • 0 in reply to Moe_BAT
    TI__Genius 11315 points

    Hey Mohammed,

    I took a look at the capture. I find it odd that there are a lot of NACKs. Disregard my comment about switching to I2C. Having the SMBus lines referenced to P- is okay. What do you mean by BQStudio is referenced to P-? You could take a look at this TIDA to see how your board compares. https://www.ti.com/tool/TIDA-00792 There is also this thread regarding ground reference connections that might help https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/823905/bq76930-bat---or-pack---or-other-ways-to-connect-gnd 

    Matt might be able to provide better insight come Monday. I appreciate your patience. 

    Thanks,
    Caleb

  • 0 in reply to Caleb Perez
    Prodigy 10 points

    Hi Caleb,

    Please find the picture below it's just to illustrate my layout  and SMBus reference. That's how the connection on the board looks like. Thank you for TIDA link I already took a look. Though my board is low-side FETs. 

    That's what i meant about the connection to bq studio (the connector) . If I only take SMBD and SMBC from the connector and disregard P- by connecting an external wire to batt-, bq studio starts not identifying the chip unless in an active state (charge, discharge). 

    Many thanks in advance for the support im just having a tough time making this work as it should. 

    Regards,

    Mohammed 

  • 0 in reply to Moe_BAT
    TI__Guru* 79143 points

    Hi Mohammed,

    With low side FETs, it is important that the EV2400 ground and BQ78350 GND are referenced to the same point. I looked at your logic analyzer capture and it looks strange to me. Are these commands you are manually sending from BQStudio?

    Thanks,

    Matt

  • 0 in reply to Matt Sunna
    Prodigy 10 points

    Hi Matt,

    I understand that but as i mentioned before i tried connecting them to the same GND (BATT-) externally. That can make bq studio not able to recognize the device. 

    I have not sent any commands manually all readings are taken by checking the scan feature. 

    An update i resoldered all connections on the SMBus lines, connection seems a lil better but errors still occur and i took another capture direct on the bq78350 Smbus pins.

    Please find it below. there are fewer NACKs to be seen but the problem is still there. Could be something with the chip?? 

    loooking forward to hearing from you guys.

    Regards,

    Mohammed  

    SMBus_direct.zip

  • 0 in reply to Moe_BAT
    TI__Guru* 79143 points

    Hi Mohammed,

    Since resoldering the connections showed improvement, I think this is most likely an issue on the board, or on the chip. You could try replacing the IC to see if it helps. There is a very large number of users for this device and SMBus NACKs is not a common problem.

    Regards,

    Matt

  • 0 in reply to Matt Sunna
    Prodigy 10 points

    Hi Matt,

    Ok thanks Matt I'll try your recommendation. 

    I'll close the thread and if something comes up i'll reopen it. 

    Best regards,

    Mohammed