ESP32 Pico V3 I/O expander

[Jinu Vijayan]

Hello, I am a student and I am trying to use tca6424a with a ESP32 PICO V3. When I upload the code for the interface and the code gets executed up to the test connection command after that it is not working the code I am using is attached below. I wrote the code in vscode using platformio.

Code: [Select all] [Expand/Collapse]

1. #include "TCA6424A.h"
2. #include <Arduino.h>
3.  
4. #define SDA 5
5. #define SCL 0
6. #define RESET_PIN 2
7.  
8. TwoWire twi(1);
9. // TCA6424A expander1(&twi);
10. TCA6424A expander2(&twi);
11.  
12. void setup()
13. {
14.   Serial.begin(115200);
15.   twi.setPins(SDA, SCL);
16.   // expander1.begin(TCA6424A_ADDRESS_ADDR_LOW);
17.   expander2.begin(TCA6424A_ADDRESS_ADDR_HIGH);
18. }
19.  
20. void loop()
21. {
22.   // Serial.print("expander1: ");
23.   // Serial.println(expander1.testConnection() ? "true" : "false");
24.   Serial.print("expander2: ");
25.   Serial.println(expander2.testConnection() ? "true" : "false");
26.   delay(1000);
27. }

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The message it is showing in the serial monitor is as folows
" expander2: [ 15][E][esp32-hal-i2c.c:142] i2cWrite(): could not acquire lock "

[rpiloverbd]

Here are some info about this error message: https://github.com/espressif/arduino-esp32/issues/834

[lbernstone]

If the WireScan example https://github.com/espressif/arduino-es ... s/WireScan doesn't show you an address, then you have an electrical problem. I don't have time to explain how I2C works, but I'll bet google does. You probably need some pullup resistors.

[Jinu Vijayan]

If the WireScan example https://github.com/espressif/arduino-es ... s/WireScan doesn't show you an address, then you have an electrical problem. I don't have time to explain how I2C works, but I'll bet google does. You probably need some pullup resistors.

I used an I2C scanner program and it sows the address of the I/O expanders and the pull up for the SDA and SCL pins are done inside the library for I2C.

[ESP_Sprite]

Those internal pull-ups are 50K or so, which is way too high for I2C. Suggest you add external pull-ups; something like 2K7 should work.

[Jinu Vijayan]

Those internal pull-ups are 50K or so, which is way too high for I2C. Suggest you add external pull-ups; something like 2K7 should work.

I did that but the problem still persists.