Microhard Telemetry Radio

Holybro Microhard Telemetry Radio integrates microhard Pico Series RF module which is capable of delivering high-performance wireless serial communications in robust topologies, such as Point to Point, Point to Multipoint and secure Mesh (Mesh only available on P900).

It uses frequency hopping spread spectrum (FHSS) technology, providing reliable wireless asynchronous data transfer between most equipment types which employ a serial interface. Fixed frequency is available on the P840 version. The radio is configured using AT commands through the Data port or using PicoConfig application through the Diagnostic Port.

P900 Radio operate within the 902-928 MHz ISM frequency band while the P840 operate within 840-845Mhz, and P400 operate within 410-480MHz. You can select your radio based on your country's available frequency band.

FCC ID: NS913P900

Feature

• USB Type-C port, integrated USB to UART converter
• 6-position JST-GH connector, can be directly connected to the TELEM port on various flight controller
• High voltage BEC onboard, Support DC7~35V voltage supply
• UART transmission LED indicator
• Three-stage RSSI LED indicator  
• Transmission within a public, license-exempt band of the radio spectrum
• Transparent, low latency link rates up to 276 kbps (P900) and 345 kbps (P860 & P400) 
• Supports a robust true Mesh operation with auto-routing (P900 Only)
• 32 bits of CRC, selectable retransmission and forward error correction
• Separate diagnostics port, transparent remote diagnostics and online network control

Specification

	P900	P840	P400-C1S
Frequency Range	902 to 928 MHz	840 to 845 MHz	410 to 480 MHz
Transmit Power (software adjustable)	100mW to 1W (20-30dBm)	100mW to 1W (20-30dBm)	100mW to 1W (20-30dBm)
Link Rate	Up to 276 kbps	Up to 345 kbps	Up to 345 kbps
Serial Baud Rate	Up to 230.4 kbps asynchronous	300 bps to 230 kbps
Spreading Method	Frequency Hopping Spread Spectrum (FHSS)	Frequency Hopping/Fixed Frequency, GMSK, 2GFSK, 4GFSK, QPSK	Frequency Hopping, GMSK, 2GFSK, 4GFSK, QPSK
Operating Modes	Mesh, Point-to-Point, Point-to-Multipoint, Store and Forward, Auto Routing, Self Healing, Packet Routing Modes	Point-to-Point, Point-to-Multipoint, Store & Forward Repeater, Peer-to-Peer
Input Voltage	DC7~35V (4-position JST-GH)
Power Consumption	Sleep < 1mA Idle 3.5mA Rx: 45mA to 98mA Tx: 1000mA to 1400mA	Sleep < 1mA Idle 20mA Rx: 45mA to 98mA Tx Peak: 2A	Sleep < 1mA Idle 20mA Rx: 45mA to 98mA Tx Peak: 2A
Error Detection	32 bits of CRC, ARQ
Antenna Gain	5dBi
Weight	44g (without antenna) 71g (with antenna)	44g (without antenna) 71g (with antenna)	44g (without antenna) 67g (with antenna)

Other Technical details and downloads can be found on the Holybro Documentation page.

Reference Links

• Ports & Button
  
• Status LED Meaning
• Default Setting
• Pinout
• Dimension
• Enabling RTS / CTS Flow Control
  
• Point-to-Multipoint Setup
• Downloads

• 1x  Microhard P840/P900/P400 Radio
• 1x  Antenna
• 1x  XT30 Power cable
• 1x  GH 6P to 6P cable 
• 1x  Metal Pin

• 2x  Microhard P840/P900/P400 Radio
• 2x  Antenna
• 2x  XT30 Power cable
• 1x  GH 6P to 6P cable 
• 1x  Metal Pin