BQ27220: BQ27220

Mykhaylo Kohut

Prodigy 10 points

Part Number: BQ27220
Other Parts Discussed in Thread: BQSTUDIO

Tool/software:

Hello,

I'm trying to configure BQ27220 with CC Delta value.

Algorithm is following:

1. Put BQ27220 to config update mode according to 6.1 Data Memory Parameter Update Example from BQ27220 Technical Reference Manual document

- unseal device

- enter full access mode

- enter config update mode

- confirm config update mode - OperationStatus() register bit 2 is set

2. Write CC Delta value - 0x488AA522

3. Read CC Delta value - 0x530aa522

4. Exit config update mode

- exit config update mode

- confirm exiting config update mode - OperationStatus() register bit 2 is clear

- seal device

My question is following - why there is different value in CC Delta? All other calibration values are correct.

Thanks,

Mykhaylo

over 1 year ago

0 Jonny over 1 year ago

TI__Mastermind 27231 points

Hello,

Can you share with me exactly what you are sending to the gauge when you are trying to write this to the gauge? It is likely that you are not correctly writing the length or checksum bytes to the gauge.

Regards,

Jonny.

0 Mykhaylo Kohut over 1 year ago in reply to Jonny

Prodigy 10 points

Hey Jonny,

Thanks for your response. Please find complete script below:

1. Unsealing

Write 0 14

Write 1 4

Write 0 72

Write 1 36

Write 0 FF

Write 1 FF

Write 0 FF

Write 1 FF

Write 0 90

Write 1 0

Read 3B 4

2. Reading current CC Delta value

Write 3E 88

Write 3F 91

Read 40 93 0A A5 22

3. Writing new CC Delta value

Write 3E 88 91 48 8A A5 22

Write 60 4D 8 (checksum)

4. Read updated CC Delta value

Write 3E 88

Write 3F 91

Read 40 93 0A A5 22

5. Sealing

Write 0 92

Write 1 0

Write 0 91

Write 1 0

Read 3B 0

Write 0 30

Write 1 0

As you can see CC Delta wasn't updated after writing.

What am I doing wrong?

Mykhaylo

0 Jonny over 1 year ago in reply to Mykhaylo Kohut

TI__Mastermind 27231 points

Hello,

It looks like you are not also sending the "ENTER_CAL" command. Please send the CAL_TOGGLE command to toggle OperationStatus()[CALMD] bit and also send the ENTER_CAL command to enter CALIBRATION mode.

Regards,

Jonny.

0 Mykhaylo Kohut over 1 year ago in reply to Jonny

Prodigy 10 points

Jonny,

Thanks for prompt response.

What should be procedure for calibration mode? Should I call CAL_TOGGLE and ENTER_CAL right after unsealing? Should update config mode be entered? How can I be sure calibration mode is set?

Also, after I read/write CC Delta should I exit calibration mode before sealing?

Please suggest,

Mykhaylo

0 Jonny over 1 year ago in reply to Mykhaylo Kohut

TI__Mastermind 27231 points

Hello,

You should unseal and full access -> CAL_TOGGLE -> ENTER_CAL.

You should send the EXIT_CAL command after sealing.

Regards,

Jonny.

0 Mykhaylo Kohut over 1 year ago in reply to Jonny

Prodigy 10 points

Hey Jonny,

I've tried to add entering calibration mode but still no luck. Please check logs below

1. Unsealing

Write 0 14

Write 1 4

Write 0 72

Write 1 36

Write 0 FF

Write 1 FF

Write 0 FF

Write 1 FF

Write 0 90

Write 1 0

Read 3B 4

2. Set calibration mode

Write 0 2D

Write 1 0

Write 0 81

Write 1 0

3. Reading current CC Delta value

Write 3E 88

Write 3F 91

Read 40 93 0A A5 22

4. Writing new CC Delta value

Write 3E 88 91 48 8A A5 22

Write 60 4D 8 (checksum)

5. Read updated CC Delta value

Write 3E 88

Write 3F 91

Read 40 93 0A A5 22

5. Exit calibration mode

Write 0 80

Write 1 0

6. Sealing

Write 0 92

Write 1 0

Write 0 91

Write 1 0

Read 3B 0

Write 0 30

Write 1 0

What can be wrong here?

0 Jonny over 1 year ago in reply to Mykhaylo Kohut

TI__Mastermind 27231 points

Hello,

Please follow the procedure in this E2E thread.

Regards,

Jonny.

0 Mykhaylo Kohut over 1 year ago in reply to Jonny

Prodigy 10 points

Thanks Jonny.

I'll try and let you know. Is there somewhere described float to hex conversion procedure for TI modules?

BR,

Mykhaylo

0 Mykhaylo Kohut over 1 year ago in reply to Mykhaylo Kohut

Prodigy 10 points

One more comment from my side. I think I've found how to convert float to hex, but that doesn't work either. There is a sentence in the manual - Use calibration routines to set this value. What are calibration routines? Where can I find an example?

Sorry still waiting for EVB to check with bqStudio

BR,

Mykhaylo

0 Jonny over 1 year ago in reply to Mykhaylo Kohut

TI__Mastermind 27231 points

Hello,

We do not have a direct conversion equation to go from hex to float and vice-versa that I can provide here. You can calibrate the gauge by using the "Calibration" tab in BQStudio.

Regards,

Jonny.

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BQ27220: BQ27220