Lup Yuen Lee 李立源 @lupyuen@qoto.org

Here's how we fixed the #BL602 Exception for #LoRa Channel Activity Detection ... Always init Stack Variables! 🙏

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/demo.c#L127-L143

Open network of #ESP32 Ground Stations to receive and operate #LoRa satellites

https://tinygs.com/

Never clear the #BL602 GPIO Interrupt Status! 🚧 ... This suppresses subsequent GPIO Interrupts 😲 ... We can now receive multiple #LoRa Packets yay!

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/sx1276-board.c#L402-L433

Let's disable #LoRa Channel Activity Detection for now ... #BL602 receives first LoRa Packet ... But not the second packet 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/demo.c

Enabled #BL602 GPIO Interrupt Handler for #LoRa SX1276 ... And BL602 hits a #RISCV Exception ... At an invalid Program Address 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/demo.c

Reconnected #PineCone #BL602 @PINE64 ... To #LoRa SX1276 pins DIO0 to DIO3 ... For testing our GPIO interrupt handler

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/sx1276.h

#BL602 now detects Multiple GPIO Interrupts ... Triggered by #LoRa SX1276 yay!

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/sx1276-board.c#L404-L461

#BL602 supports only one Interrupt Handler for all GPIO Pins ... Let's iterate thru the #LoRa SX1276 Interrupts and handle them

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/sx1276-board.c#L404-L461

#BL602 now displays the #LoRa Packet received from #WisBlock yay!

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/demo.c

#BL602 #LoRa Exception happened because we passed a pointer to a stack object ... Which gets used by the Interrupt Handler 😲 ... This works OK in the original Mynewt code, but not for BL602

https://gist.github.com/lupyuen/1539f9dd52e9a83d4fbe7724481112bf

Oops the Program Counter for our #RISCV Exception is null ... So there must be a missing Callback Function somewhere in our #LoRa #BL602 Firmware 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/demo.c

Aha! #BL602 hits a #RISCV Exception ... When processing the received #LoRa Packet! Let's follow these steps to troubleshoot...

https://lupyuen.github.io/articles/i2c#appendix-how-to-troubleshoot-risc-v-exceptions

#LoRa Packet goes from #WisBlock Transmitter ... To #BL602 SX1276 Interrupt Handler ... To #FreeRTOS Task yay! Now we read the received LoRa Packet from SX1276 over SPI

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/demo.c

Let's use the Event Queue to forward the #LoRa Packet Received Interrupt ... From #BL602 Interrupt Handler ... To the #FreeRTOS Application Task

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/sx1276-board.c#L408-L441

NimBLE Porting Layer builds OK on #RISCV #BL602 #FreeRTOS yay! ... Let's call these Event Queue functions to process our received #LoRa Packets

https://lupyuen.github.io/pinetime-rust-mynewt/articles/dfu#nimble-event-queue-functions

NimBLE Porting Layer hasn't been ported ... To #RISCV ? 🤔 ... Let's fix this for #BL602 #LoRa

https://github.com/apache/mynewt-nimble/blob/master/porting/npl/freertos/src/npl_os_freertos.c#L25-L30

Maybe #PineTime can help #BL602! ... The NimBLE Porting Layer defines Multitasking Functions for #FreeRTOS ... Let's call them to handle #LoRa Interrupts

https://lupyuen.github.io/pinetime-rust-mynewt/articles/dfu#nimble-stack-for-bluetooth-le-on-pinetime

Now that #BL602 can handle #LoRa Packet Received Interrupt ... Let's defer the LoRa Packet Processing from the Interrupt Handler to the Application Task ... How shall we do this in FreeRTOS? 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/sx1276-board.c#L404-L438

#BL602 GPIO Interrupts hanging could be due to the way we handle multiple GPIO Interrupts ... Let's revisit this when we can trigger multiple GPIO Interrupts from #LoRa SX1276

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/sx1276-board.c#L145-L196

#BL602 GPIO Interrupt triggered OK when #LoRa Packet received yay! ... But why does it work now? 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/lorarecv/customer_app/sdk_app_lora/sdk_app_lora/demo.c