Lobaro Pressure and Temperature Sensor
To read out the pressure & temperature probe, the Hybrid Modbus Gateway must be configured as follows:
Parameter | Value | Comment |
---|---|---|
WAN | lorawan | For LoRaWAN OTAA usage. |
PlFmt | 5 | Sets the payload to a short format. |
MbCmd | 0 0/5 * * * *:R,9600,8N1:010300160002,010300260002,fa0400050001 | Reads the Registers 22-23, 34-35 and internal Register 5. fa0400050001 reads the battery voltage and is optional. The CRON Expressions can be adjusted to set time of sensor reading. |
PowerOnDelay | 1500 | Battery variant only. Sets time (in ms) between activating sensor power and reading value (time for sensor to be ready). |
Data Uplink (Port 20)
Bytes | 0 . | 1 . 2 . 3 . 4 . | 5 . 6 . 7 . 8 . | 9 . 10 . |
------+--------+-----------------+-----------------+----------+
Field | Header | Pressure | Temperature | Voltage |
Field | Type | Value |
---|---|---|
Header | uint8 | 0x00 on success, 0x80 if an error occurred |
Pressure | float32 | Pressure in mH2O , ffffffff on error. |
Temperature | float32 | Temperature in |
Voltage | uint16 | Voltage in mV, ffff on error |
Example
# Example of a successful measurement '003d94ce4541b7a5120da8' '00' -> Successful readout '3d94ce45' -> 0.073 mH2O '41b7a512' -> 22.96 °C '0da8' -> 3496 mV / 3.496 V # Example '80ffffffffffffffff' '80' -> An error occurred. 'ffffffff' -> Pressure could not be read. 'ffffffff' -> Temperature could not be read. 'ffff' -> Voltage could not be read.
Reference Parser
see below
Lobaro Pressure Sensor
Reading from the Lobaro Pressure Sensor using the Hybrid Gateway can be done by setting the following parameters in the configuration:
Parameter | Value | Comment |
---|---|---|
WAN | lorawan | For LoRaWAN OTAA usage. |
PlFmt | 5 | Sets the payload to a short format. |
MbCmd | 0 0/5 * * * *:R,9600,8N1:010300040001,fa0400040001,fa0400050001 | Reads the register 4 inside probe and 4 and 5 inside Bridge. fa0400050001 reads the battery voltage and is optional. The CRON Expressions can be adjusted to set time of sensor reading. |
PowerOnDelay | 1500 | Battery variant only. Sets time (in ms) between activating sensor power and reading value (time for sensor to be ready). |
Data Uplink (Port 20)
Bytes | 0 . | 1 . 2 . | 3 . 4 . | 5 . 6 . |
------+--------+----------+-------------+---------|
Field | Header | Pressure | Temperature | Voltage |
Field | Type | Value |
---|---|---|
Header | uint8 | 0x00 on success, 0x80 if an error occurred |
Pressure | int16BE | Pressure in mmH2O |
Temperature | int16BE | Temperature in °C inside Bridge |
Voltage | int16BE | Voltage in mV, ffff on error |
Example
# Example of a successful measurement '000211001a0da8' '00' -> Successful readout '0211' -> 529 -> 0.529 mH2O '001a' -> 26 -> 26°C (inside Box) '0da8' -> 3496 -> 3496 mV / 3.496 V
Reference Parser
Pressure Probe Parser
/** * Parser for Lobaro Pressure Probe via LoRaWAN (hybrid gateway). * Usable for Pressure Probe as or with Presure+Temperature Probe. * Works with TTN, ChirpStack, or the Lobaro Platform. */ function signed(val, bits) { // max positive value possible for signed int with bits: var mx = Math.pow(2, bits-1); if (val < mx) { // is positive value, just return return val; } else { // is negative value, convert to neg: return val - (2 * mx); } } function int16_BE(bytes, idx) { bytes = bytes.slice(idx || 0); return signed(bytes[0] << 8 | bytes[1] << 0, 2*8); } function uint16_BE(bytes, idx) { bytes = bytes.slice(idx || 0); return bytes[0] << 8 | bytes[1] << 0; } function uint32_BE(bytes, idx) { bytes = bytes.slice(idx || 0); return bytes[0] << 24 | bytes[1] << 16 | bytes[2] << 8 | bytes[3] << 0; } function float32FromInt(asInt) { var sign = (asInt & 0x80000000) ? -1 : 1; var exponent = ((asInt >> 23) & 0xFF) - 127; var significand = (asInt & ~(-1 << 23)); if (exponent === 128) return null; // return sign * ((significand) ? Number.NaN : Number.POSITIVE_INFINITY); if (exponent === -127) { if (significand === 0) return sign * 0.0; exponent = -126; significand /= (1 << 22); } else significand = (significand | (1 << 23)) / (1 << 23); return sign * significand * Math.pow(2, exponent); } function float32_BE(bytes, idx) { return float32FromInt(uint32_BE(bytes, idx)); } /** * TTN decoder function. */ function Decoder(bytes, port) { var vals = {}; if( port == 20 ){ if (bytes.length==5) { // Pressure Probe without temperature sensor and Bridges internal Temperature vals["error"] = !!(bytes[0]&0x80); vals["pressure"] = int16_BE(bytes, 1)/1000; vals["temperature"] = int16_BE(bytes, 3); } else if (bytes.length==7) { vals["error"] = !!(bytes[0]&0x80); vals["pressure"] = int16_BE(bytes, 1)/1000; vals["temperature"] = int16_BE(bytes, 3); vals["voltage"] = uint16_BE(bytes, 5) / 1000; } else if (bytes.length==9) { vals["error"] = !!(bytes[0]&0x80); // pressure in mH2O vals["pressure"] = float32_BE(bytes, 1); // temperature in Degree Celsius vals["temperature"] = float32_BE(bytes, 5); } else if (bytes.length==11) { vals["error"] = !!(bytes[0]&0x80); // pressure in mH2O vals["pressure"] = float32_BE(bytes, 1); // temperature in Degree Celsius vals["temperature"] = float32_BE(bytes, 5); vals["voltage"] = uint16_BE(bytes, 9) / 1000; } } return vals; } /** * TTN V3 Wrapper */ function decodeUplink(input) { return { data: { values: Decoder(input.bytes, input.fPort) }, warnings: [], errors: [] }; } /** * ChirpStack decoder function. */ function Decode(fPort, bytes) { // wrap TTN Decoder: return Decoder(bytes, fPort); } /** * Lobaro Platform decoder function. */ function Parse(input) { var data = bytes(atob(input.data)); var port = input.fPort; return Decoder(data, port); }