ANT Forum

Hi,

I have a ANTAP281M4IB module in a battery powered device. If the supply voltage is 3.0V (or above) everything works fine. If the supply voltage is below 3.0V (e.g. 2.9V) the ant module will not respond. But according to the datasheet, the module should work.

Some details:
* ANTAP281M4IB
* async mode, 19200 bps
* RESET (0), SUSPEND (1) and SLEEP (0) are connected to mcu and have values in brackets all time.

In any case RTS of ANT module goes to zero after power up. But if voltage is below 3.0V the module will not answer to any serial packet. That means that there is no response on TXD and RTS stays zero.

I have checked all pins with my scope. All levels seem to be fine. I also double checked VCC and RESET-Pins on drops/spikes.

Any idea?      

Hi there,
It seems that the AP2 module which you are using is the known issue of the product. Please refer to the document for the detail: http://www.thisisant.com/assets/resources/Datasheets/D00001363_AP2_RF_Transceiver_Module_Revision_History_Rev1.5.pdf.

If it is for the purposes of prototype, the module still can be used. To manufacture products, we would recommend contract your local distributer, and replace it.