OSOM (read as ˈôsəm) is the acronym of Open Speedometer.
The new architecture is the following:
Clinet <==BLE==> Master <==2.4GHz==> Slave
where:
- Master: CC2541 <==UART==> PIC <==SPI==> nRF24L01+
- Slave: PIC <==SPI==> nRF24L01+
The client is a device that must be compatible with BLE (Bluetooth 4.x).
The CC2541 (aka NP, aka Network Processor) will run a standard firmware that is in charge of providing a bluetooth connection to the PIC.
Master and Slave will exchange messages over a custom, light-weight, protocol.
- Microcontroller: PIC32MX274F256D @72MHz (TODO verify)
- Communication:
- Bluetooth (master only): HM10 Bluetooth 4.2 Low Energy
- Wireless: nRF24L01+ @2.4GHz
- Power:
- LiPo 1s Battery, 1200/2000 mAh (not choosen yet)
- 5V provided by micro USB, 500 mA MAX
- Sensor: custom made 650nm modulated laser sensor
- Laser source: Red diode laser, 650nm @5mW
| PIN | I/O | PPS | Function | Note |
|---|---|---|---|---|
| 6 | IN | RPB2 | U1RX | PIC <== NP |
| 7 | OUT | RPB3 | U1TX | PIC ==> NP |
| PIN | I/O | PPS | Function | Note |
|---|---|---|---|---|
| 21 | IN | RPB10 | INT1 | Interrupt generated by nRF24L01+ |
| 22 | OUT | RPB11 | SDO2 | |
| 23 | OUT | - | CS | RB12 |
| 24 | IN | RPB13 | SDI2 | |
| 25 | OUT | - | CE | RB14 |
| 26 | OUT | RPB15 | SCK2 |
| PIN | I/O | PPS | Function | Note |
|---|---|---|---|---|
| 4 | OUT | RPB0 | U2TX | PIC ==> PC |
| 5 | IN | RPB1 | U2RX | PIC <== PC |
USB will be available too, with at least a comunication device class (CDC) enumeration.
| PIN | I/O | PPS | Function | Note |
|---|---|---|---|---|
| 16 | IN | - | INT0 | Left IN Interrupt |
| 11 | IN | RPB4 | INT4 | Right IN Interrupt |
New PIC analisys required
Analisys required.
Note
- Master only: an extra LED from CC2541 indicates the BT connection status.
- From the battery charger an extra LED indicates che charging status.