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Controlling the Radio Performance in API 6

You can control the transmitter power output Simple Hardware devices transmit messages with through the firmware. In default, the devices are shipped to you in the respective RC zone for your region, but if your device is multizone and has a power amplifier assembled (default for RC2 and RC4), you can also use it in RC⅓/⅚/7.

In addition to this, it is also possible to switch the data rate from 100 bps to 600 bps.


We use the power amplifier in order to transmit on the radio frequencies required by RC2/4.


There are two downlink registers you will work with if you want to adjust the radio performance of Simple Hardware devices: 0x53 and 0x54.

0x53 controls the use of the power amplifier in RC⅓/⅚/7 and 100/600 bps bitrate and 0x54 controls the power output of the device; upper bits 7-4 increase or decrease the voltage through a switched-mode power supply and the lower bits 3-0 adjust attenuation.


Please note that the devices are calibrated perfectly fine from the factory and adjusting radio performance should be done only in certain situations. Please contact us if you are interested in more information!

Using the power amplifier in multizone devices in RC⅓/⅚/7

Multizone devices with a power amplifier that's turned off will have lower radio performance in RC⅓/⅚/7 (by 1.5 dBm) because of the more complicated radio path. This is compared to devices without a power amplifier (that cannot work in RC2/4).

You can turn the power amplifier on with bit 7 of register 0x53.

The output of a multizone device with an active power amplifier in RC⅓/⅚/7 will be 22 dBm (which is not legal in RC1), but you can fine-tune this by decreasing the tx power voltage with register 0x54. The value of bits 7-4 should be around 1-3.


Please note that this will increase power consumption per message by 50 percent. It's useful in use cases where the device is integrated into another device (e.g.fridge, cooler, manhole). In this case, you can increase the power output and certify the device as whole.

Using 600 bps instead of 100 bps

You can switch to using 600 bps bitrate instead of the default 600 bps by turning on bit 6 of register 0x53.