Lup Yuen Lee 李立源 @lupyuen@qoto.org

Someone captured this #LoRa Chirp with HackRF One SDR ... Isn't this beautiful?

https://www.linkedin.com/feed/update/urn:li:activity:6772707414933430272?commentUrn=urn%3Ali%3Acomment%3A%28activity%3A6772707414933430272%2C6772744850791124992%29

Captured the Legendary #LoRa Chirp! (The helix thingy)

https://pubs.gnuradio.org/index.php/grcon/article/download/8/7/

1️⃣ Enable #LoRa SX1276 Power Amplifier 2️⃣ Increase Airspy sample rate to 10 MHz ... LoRa Packets never looked better!

https://github.com/lupyuen/bl_iot_sdk/commit/ae7e11a87f58ef63fea9b5c158aa66f3e81c145e#diff-6d25e21aa14e973456e3eb35c4298a576f14a5296ae392544e1ca61d8e463ed4

"Testing #LoRa with #SDR and some handy tools"

https://penthertz.com/blog/testing-LoRa-with-SDR-and-handy-tools.html

Let's zoom into the #BL602 #LoRa Packet ... And hunt for the LoRa Chirp!

https://pubs.gnuradio.org/index.php/grcon/article/download/8/7/

CubicSDR software works better with Airspy ... Here's the #BL602 #LoRa Packet (64 bytes) centered at 923 MHz with bandwidth 125 kHz

https://cubicsdr.com/

Nope Airspy SDR couldn't sniff our #BL602 #LoRa at 923 MHz ... Though it sniffed others thru the Faraday Cage (erm) Pot 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/demo.c#L220-L270

#BL602 + #LoRa SX1276 + Airspy SDR ... Inside an improvised Faraday Cage 🫕 ... It really works!

But today we shall spy on #BL602 + #LoRa ... With an #Airspy R2 Software Defined Radio 📻

Someday we shall pack #PineCone #BL602 @ThePine64 with #LoRa ... Into this cute clear Junction Box

#BL602 sends a #LoRa message ... By copying the message to SX1276 Transmit FIFO over SPI ... Was the message actually transmitted? Airspy will tell!

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/demo.c#L107-L124

#BL602 inits the #LoRa SX1276 Driver ... By writing a bunch of SX1276 Registers over SPI ... So far so good!

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/demo.c#L220-L270

How will we know if our #BL602 + #LoRa SX1276 are misbehavin’ on the airwaves? We got a spy ... An AirSpy Software Defined Radio

https://airspy.com/airspy-r2

Our #LoRa SX1276 (actually RF96) is factory configured for 434 MHz, sez the Frequency Registers ... #BL602 will tune it to 923 MHz for Singapore

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/demo.c#L199-L213

#BL602 #SPI Unsolved Mystery ... BL602 must be configured for SPI Phase 1 to talk to #LoRa SX1276 ... But SX1276 actually uses SPI Phase 0! 🤔

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/sx1276-board.c#L112-L137

Yep #BL602 talks OK to #LoRa SX1276 over SPI ... SX1276 register values look correct ... Now let's transmit a LoRa Message!

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/demo.c#L199-L213

Let's test whether #BL602 can talk to #LoRa SX1276 over SPI ... By dumping some SX1276 registers

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/demo.c#L199-L213

#PineCone #BL602 nearly out of pins (and colours) for #LoRa SX1276 ... Let's use these pins for now

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/sx1276.h#L24-L54

Let's test the #BL602 #LoRa Driver ... With the "LoRa Ping" app ported from #Mynewt OS

https://github.com/apache/mynewt-core/blob/master/apps/loraping/src/main.c

#BL602 IoT SDK builds #LoRa Driver successfully yay! Now filling in the SPI Functions to talk to SX1276

https://github.com/lupyuen/bl_iot_sdk/blob/lora/customer_app/sdk_app_lora/sdk_app_lora/sx1276.c#L213-L252