First tests of the NrfLoader are underway. [NrfLoader] is a project to implement an Over-the-Air bootloader for PIC16F1823/25 based devices, via the NRF24L01 RF modules. The NRF24L01 is connected to the PIC via 4-wire SPI interface (MISO/MOSI/CS/CLK), and can provide up to a 2Mbps wireless connection. I have a series of these already in operation, but with a fixed software image, making updates and upgrades a pain. The NRFLoader is loosely based on the [PIC16F1-USB-Bootloader]. as with the USB loader the NRFLOADER is hand crafted PIC Assembler, and fits within the first 512 bytes of the target PIC, so even small devices limited to 2K of FLASH space, can benefit from this code.
Testing is still ongoing, using an Arduino UNO connected to a NRF radio, in order to packetize the write requests. When completed I hope to have a WIFI-to-NRF bridge that will allow me to detect and update devices without the need of the arduino.
To do: Finish integration testing, and setup the AUDIT message that would provide a checksum test for the entire flash image, ensuring integrity before we allow control to jump to the uploaded function.
Stay tuned for more.
NrfLoader – an OTA solution for PIC uControllers
