License: GPLv2
This user interface does not currently RX or TX with the hardware. In fact, the FPGA HW is currently being worked here: https://github.com/M17-Project/OpenHT-hw. The goal is to show a Proof of Concept (PoC) of RX and TX with different modes, including FM, M17, FreeDV, etc. As with any open source project, help is wanted. So if you are excited about the possibility to OWN your own radio and be able to use/modify/extend without asking for permission. Come join us!
Note: Don't forget to initialize submodule (OpenHT-fw/Drivers/lvgl) to pull in lvgl source, currently using v8.3.6 tag.
Note: When generating C files with SL Studio the destination must be in OpenHT-fw/Core/Src/lvgl_ui
- MCU will target the STM32F469I-DISCO Discovery board
- OpenHT FPGA board will interface with the existing DISCO Arduino headers
Together they will create the OpenHT PoC. (TX power will be extremely limited on PoC)
The OpenHT FPGA board contains the speaker, FPGA, RF, power distribution, PTT and Power switches. The MCU is the OpenHT control interface. It contains the touchscreen user interface, the microphone, flash memory and USB interface.
When the PTT button is pressed by the operator, the MCU (over SPI) will instruct the FPGA board to begin transmitting and will then provide the audio or baseband data samples to the FPGA board for transmission. Once transmission is complete the MCU will instruct the FPGA board to switch to receive mode. Any received signal will be sent by the FPGA board to the MCU for conversion into audio based on the radio mode setting.
| Callsign | Frequency |
|---|---|
 |
 |
First, AT86RF215 needs to be initialized to accept (and output) I/Q baseband over LVDS:
AT86_ConfigCommon();
After that's done, the chip needs to be tuned to the required frequency for either transmission or reception:
AT86_TX09(433475000, 2.0f, 0x13);
AT86_TX24(2400000000, 1.1f, 0x17);
AT86_RX09(433475000+40000, 1.1f, 1, 0);
AT86_RX24(2400000000+40000, 1.1f, 1, 0);
AT86_xXnn - x -> R=reception, T=transmission; nn -> 09=sub-GHz or 24=2.4GHz
The parameters are as follows:
- frequency in Hz, for RX add frequency translation of 40kHz,
uint32_t - frequency correction in ppm (float)
- for TX: power setting, 0-23 (0=min, 23=max)
- for RX: AGC enable (0=disabled, 1=enabled) and AGC target level (0=max, 7=min)
It's assumed that two uint16_t variables are declared: reg_addr and reg_val. Additionally, one array of uint8_t is needed to hold the data for SPI transfer.
reg_addr=REG_WR|CR_1;
reg_val=MOD_FM|PD_ON|DEM_FM|BAND_09;
...
reg_addr=REG_WR|CR_2;
reg_val=CTCSS_TX_NONE|STATE_RX|FM_TX_N;
...