RE: DTM Example Firmware Bug ?

FormerMember — Tue, 04 Apr 2017 13:03:45 GMT

SDK 12.0.0 and later supports negative TX power:

/**@brief Function for configuring the output power for transmitter test.
      This function may be called directly, or through dtm_cmd() specifying
      DTM_PKT_VENDORSPECIFIC as payload, SET_TX_POWER as length, and the dBm value as frequency.
*/
bool dtm_set_txpower(uint32_t new_tx_power)
{
// radio->TXPOWER register is 32 bits, low octet a signed value, upper 24 bits zeroed
int8_t new_power8 = (int8_t)(new_tx_power & 0xFF);

// The two most significant bits are not sent in the 6 bit field of the DTM command.
// These two bits are 1's if and only if the tx_power is a negative number.
// All valid negative values have the fourth most significant bit as 1.
// All valid positive values have the fourth most significant bit as 0.
// By checking this bit, the two most significant bits can be determined.
new_power8 = (new_power8 & 0x30) != 0 ? (new_power8 | 0xC0) : new_power8;

if (m_state > STATE_IDLE)
{
    // radio must be idle to change the tx power
    return false;
}

m_tx_power = new_power8;

return true;

}

RE: DTM Example Firmware Bug ?

endnode — Tue, 04 Apr 2017 11:06:13 GMT

Here are some references to past issues in DTM example from nRF5 SDK.

RE: DTM Example Firmware Bug ?

endnode — Tue, 04 Apr 2017 10:57:14 GMT

Yes, there were couple of bugs in Vendor Specific DTM commands (used by Nordic for Tx Power settings), there were even some Q&S on this forum and it use to be listed in known issues of particular SDK releases...