My First #RISCV Exception on #PineCone #BL602 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/i2c/customer_app/sdk_app_i2c/sdk_app_i2c/demo.c#L234-L308

Let's hunt for MEPC (Machine Exception Program Counter) 0x2300 8fe2 in the #RISCV Disassembly ... Yep my buggy code crashed in the #BL602 I2C Interrupt Handler 🤔

https://github.com/lupyuen/bl_iot_sdk/releases/download/v1.0.1/sdk_app_i2c.S

Here's how we dump the #RISCV Disassembly from the #BL602 ELF Executable

https://github.com/lupyuen/bl_iot_sdk/releases/tag/v1.0.1

Found the bug in my #BL602 I2C program ... There are two levels of BL602 I2C API: 1️⃣ High Level (which calls FreeRTOS) 2️⃣ Low Level (which doesn't call FreeRTOS) ... I'm using the Low Level API, so I shouldn't call "hal_i2c_init" in the High Level API

https://github.com/lupyuen/bl_iot_sdk/blob/i2c/customer_app/sdk_app_i2c/sdk_app_i2c/main.c#L187-L190

#BL602 I2C program doesn't crash now ... But it doesn't read any data from the BME280 Sensor 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/i2c/customer_app/sdk_app_i2c/sdk_app_i2c/demo.c#L216-L308

When the #BL602 I2C HAL looks dubious ... Refer to the BL602 Reference Manual!

https://github.com/bouffalolab/bl_docs/tree/main/BL602_RM/en

Why my #BL602 I2C Program crashed ... And the 2 levels of BL602 I2C HAL

https://github.com/lupyuen/bl_iot_sdk/releases/tag/v1.0.1

Testing BME280 I2C Sensor with Bus Pirate ... While figuring out why it doesn't respond to #BL602 🤔

http://dangerousprototypes.com/docs/I2C

#BME280 I2C Sensor tested OK with Bus Pirate ... Now to make it work with #BL602 🤔

http://dangerousprototypes.com/docs/I2C

Shall I use Bus Pirate to sniff the I2C Bus on #BL602? 🤔

http://dangerousprototypes.com/docs/I2C#I2C_Bus_Sniffer_macro

Oops I need to Write To MEN (heh heh) after setting the #BL602 I2C Registers ... Lemme Write To MEN now

https://github.com/bouffalolab/bl_docs/tree/main/BL602_RM/en

#BL602 #I2C still no go after writing to MEN ... Let's hook on to the I2C Interrupts and observe what happens

https://github.com/bouffalolab/bl_docs/tree/main/BL602_RM/en

Here's our simple #BL602 I2C Interrupt Handler ... When we hit an I2C Interrupt, bump up the Interrupt Counters ... Remember: No funny business allowed in Interrupt Handlers (like Console Output)

https://github.com/lupyuen/bl_iot_sdk/blob/i2c/customer_app/sdk_app_i2c/sdk_app_i2c/demo.c#L226-L251

After counting the #BL602 I2C Interrupts ... We now see 2 I2C problems: No Acknowledge and FIFO Error 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/i2c/customer_app/sdk_app_i2c/sdk_app_i2c/demo.c#L216