Donate to support Open Hardware3xAAA battery powered DS18B20 temperature sensor. It is a low power consumption temperature sensor. The prototype is ready and tested.
Technical Specification
Dimensions D 71 mm x H 49 mm THT and SMD NRF24 radio module footprint Reset Button Bootloader header FTDI header for programming MIC5219-3.3BM5 TR Voltage regulator One-Wire Digital DS18B20 Temperature sensor High Accuracy Temperature Sensor ±0.5°C at –10°C to +85°C Measures Temperatures from -55°C to +125°C Supply voltage 2.5-12V Battery voltage sensors via divider
Related Project
3xAAA battery powered DS18B20 temperature sensor is part of PiHome Smart Heating project.
Assembly
The PCB is almost SMD apart from AAA battery holder and on/off sliding switch. The silkscreen layer indicates all components and their respective values, all capacitors are non polarized. on power on led blink once and then second blink after connection to gateway.
3xAAA battery supply enough power for this sensors to work for over one year with temperature reading every 60second (aprox). temperature is compared to previous reading and same for battery level with voltage divider, reading are only sent if different from previous.
MySensors Custom Settings:
| Code | Function |
|---|---|
| #define MY_DEBUG | Enable debug prints to serial monitor |
| #define MY_SPLASH_SCREEN_DISABLED | This saves 120 bytes of flash |
| #define MY_SIGNING_SIMPLE_PASSWD "pihome" | Enable Signing |
| #define MY_ENCRYPTION_SIMPLE_PASSWD "pihome" | Enable Encryption This uses less memory, and hides the actual data. |
| Radio Related | |
| #define MY_RADIO_RF24 | Enable and select radio type attached |
| #define MY_RF24_IRQ_PIN 8 | nRF24 IRQ Pin on Arduino |
| #define MY_RF24_PA_LEVEL RF24_PA_MIN | Set LOW transmit power level as default, if you have an amplified NRF-module and power your radio separately with a good regulator you can turn up PA level. RF24_PA_MIN RF24_PA_LOW RF24_PA_HIGH RF24_PA_MAX RF24_PA_ERROR |
| #define MY_RF24_CHANNEL 91 | RF channel for the sensor net, 0-127 Default is 76 |
| #define MY_NODE_ID 30 | PiHome - Make Sure you change Node ID, for each temperature sensor. 21 for Ground Floor, 20 for First Floor, 30 for Domastic Hot Water |
| #define MY_RF24_DATARATE RF24_250KBPS | RF24_250KBPS for 250kbs, RF24_1MBPS for 1Mbps, or RF24_2MBPS for 2Mbps |
Ps: its work in process... i m always learning hence: all comments and recommendations are welcome.
| Qty | Value | Device | Package | Parts | Description | MF | MPN | Aliexpress or Ebay link |
|---|---|---|---|---|---|---|---|---|
| 2 | 22pF | Capacitor | ||||||
| 4 | 0.1nF | Capacitor | ||||||
| 1 | 10uF | Capacitor | ||||||
| 1 | 2.2uF | Capacitor | ||||||
| 1 | 470pf | Capacitor | ||||||
| 1 | MIC5219-3.3YM5_TR | LDO Regulator | ||||||
| 1 | nRF24L01 THT/ SMD nRF24L01 | LDO Regulator | ||||||
| 1 | 1M | Resister | ||||||
| 1 | 10K | Resister | ||||||
| 1 | 100K | Resister | ||||||
| 1 | 220ohm | Resister | ||||||
| 1 | 4.7k | Resister | ||||||
| 1 | MOMENTARY-SWITCH-SPST-SMD-6.0X3.5MM | TACTILE_SWITCH_SMD_6.0X3.5MM | ||||||
| 1 | DS18B20 | Temperature Sensor | ||||||
| 1 | THT AAA Battery Holder | Battery Holder | ||||||
| 1 | ATMEGA328p_au | ATMEGA328 | ||||||
| 1 | HC49SDLF-8.00MHZ | HC49SDLF-8.00MHZ |
| Name | Size | # Downloads |
|---|---|---|
| Other.gbr | 1.36 kB | 291 |
| copper_bottom.gbr | 101.56 kB | 353 |
| copper_top.gbr | 189.68 kB | 302 |
| drills.xln | 1.56 kB | 289 |
| gerber_job.gbrjob | 581 B | 308 |
| profile.gbr | 12.02 kB | 291 |
| silkscreen_bottom.gbr | 11.98 kB | 333 |
| silkscreen_top.gbr | 81.72 kB | 286 |
| soldermask_bottom.gbr | 2.64 kB | 338 |
| soldermask_top.gbr | 4.31 kB | 303 |
| solderpaste_bottom.gbr | 148 B | 284 |
| solderpaste_top.gbr | 1.82 kB | 288 |
| Name | Size | # Downloads |
|---|---|---|
| PiHome_Battery_Temperature_Sensor_v031.ino | 7.55 kB | 356 |