BQ25713EVM-017: Device ACK Error

Hey Victoria,

What is the state of jumpers JP2, JP3, and JP4?

You also mention that VSYS is 3.6V, not 5V. Where did you get the value of 5V from? Have you also attempted to use the charger as described in the EVM User's Guide to see if communicate works there?


Regards,
Joel H

Hi,
For what it is worth, with my EV2400 I found that I get "Device ACK Error" if the connection and power-up sequence is wrong.
I have to power-up the board, connect the EV2400, then plug the EV2400 into the PC via USB, then start the software.
Then it can read and write the registers ok.
PS: When it came to do my own PCB I found that the I2C on the EV2400 was picky about the value of the pull-up resistors on the SCL and SDA lines. 10K resistors worked, but 1K resistors didn't work, and the symptom of this was seeing a "Device ACK Error" in the software.

Hi Joel, 

I have only one cell connected, so JP2,3,4 are OFF.  The rest of the jumpers (JP1, JP8 and JP5) are ON. CHG_OK led is ON too.

I have measured VSYS at J6, and it is 3.6V. I thought that, if the VIN (5V in my case) and the battery are connected, VSYS would be 5V. Please, let me know if I am wrong.

I have followed the steps of the user's guide, and it isn't work properly. I also try the proposal of power up sequence but I can't connect to the charger (Device ACK Error).

Do you have any idea or suggestion?

Thank you so much!

Hey Nic,

To your comment, I'm not sure if we asked if you tried removing your pull-up resistors and trying to communicate solely with the EV2400. It has its own rail internally.


Regards,
Joel H

Hey Victoria,

The minimum system voltage for a 1S configuration is 3.6V. This is the correct operation. Additionally, this 1S configuration clamps the maximum system voltage to 5V. Now, you may change the minimum system voltage to be around 5V via register REG0x0D but you would also have to change the cell configuration or battery voltage selected in the registers.

Do you have waveform of the I2C communication you can provide? Also try removing JP8 to remove the LDO pullup from the circuit. Also make sure JP6 is not installed.


Regards,
Joel H

Dear Joel,
I am aware that the EV2400 also has its own internal 20K pull-ups, but my PCB still needs its own SCL and SDA pull-up resistors for when the I2C is controlled by my PCB's own micro-controller.

I have found that 10K pull-ups on the PCB works fine.

Regards,

Nicholas Lee

Hi Joel,

I realized that the problem is the EV2400. The PC does not recognize the device.

When I connected it to the PC, the leds of the EV2400 are ON, but the PC doesn't sounds(when you connect an USB it has to sound).
I have open the box, and I install the JP7 and suddenly the PC sounds, but li8ke an unknown device. If I disconnect the jumper, the PC sounds again, like unplugged usb.

I tried to update the firmware, like your workmates said in another forum, but it shows:

c:\ti\EV2400Updater-0.18>EV2400_Updater_v0018.exe -s
Skipping putting EV2400 in FWUpdate mode.
Performing Mass Erase...
Traceback (most recent call last):
File "<string>", line 144, in <module>
File "C:\projects\EV2400\ev2400files\updater\build\updater\out00-PYZ.pyz\msp430.bsl5.hid", line 213, in open_connection
File "C:\projects\EV2400\ev2400files\updater\build\updater\out00-PYZ.pyz\msp430.bsl5.hid", line 101, in open
ValueError: USB VID:PID 2047:0200 not found (not in BSL mode? or try --device)

I ran it in administrator mode, with and without jumper.

I am lost. I don't know anything else to try.

Any idea?

Hey Victoria,

Can you take a scope capture of the I2C waveform on the board? We want to probe both SDA and SCL lines with respect to ground during a communication. 

And just to ask the questions: is the I2C address you have on BQStudio the correct one for the device? And also, is the cable for the EV2400 on the on the I2C side and not the SMBus side?

Regards,

Joel H

Hi Joel, 

I can't send you any capture of the I2C because the PC doesn't recognize the EV2400, so I have not communication and I can't connect it to the BQStudio. It shows: no free adapters are available for use on this system. 

Anyway, I have connected it to the I2C side and selected D6(6B).

Regards.

Dear Victoria,

This is purely based on my own experience, but I had the same initial USB problems with the EV2400.

Opening "Device Manager" from the control panel in windows, you should be able to see all the USB devices plugged into your PC.

The EV2400 (when it works) should show up under the "Human Interface Devices" as a "USB Input Device", using Microsoft's own built-in driver.
It is completely generic and non-descript, and doesn't even mention it is an EV2400.
(NB: I am using Windows 8 Pro)

The EV2400 is a bus-powered device so make sure it is plugged into a USB port that can supply enough power (and preferably not into a bus-powered extension hub).

Mine also only worked after I had unplugged some other USB devices. This could be a pure coincidence, or it could be a clash, but it is worth trying.

Good luck.
Regards,
Nicholas Lee