LoRa(mode=LoRa.LORAWAN, region = LoRa.US915) uses the wrong frequency table for the US #270
Description
(sysname='LoPy', nodename='LoPy', release='1.18.2', version='v1.8.6-849-743b7e7 on 2019-01-21', machine='LoPy with ESP32', lorawan='1.0.2', pybytes='0.9.6')
Cannot join the TTN network using the default US channels in the Lopy.
pycom/pycom-micropython-sigfox/blob/master/lib/lora/mac/region/RegionUS915.c set the channels from 902.3 to 903.7MHz
void RegionUS915InitDefaults( InitType_t type )
{
switch( type )
{
case INIT_TYPE_INIT:
{
// Channels
// 125 kHz channels
for( uint8_t i = 0; i < US915_MAX_NB_CHANNELS - 8; i++ )
{
Channels[i].Frequency = 902300000 + i * 200000;
Channels[i].DrRange.Value = ( DR_3 << 4 ) | DR_0;
Channels[i].Band = 0;
}
The correct channelization is 903.9 to 905.3MHz and can be found at
https://www.thethingsnetwork.org/docs/lorawan/frequency-plans.html
Adding this code fragment after creating a lora object will allow the Lopy to reliably join the TTN network
lora = LoRa(mode=LoRa.LORAWAN, region = LoRa.US915)
for index in range(0, 7):
lora.remove_channel(index)
for index in range(16, 72):
lora.remove_channel(index)
lora.add_channel(8, frequency=903900000, dr_min=0, dr_max=3)
lora.add_channel(9, frequency=904100000, dr_min=0, dr_max=3)
lora.add_channel(10, frequency=904300000, dr_min=0, dr_max=3)
lora.add_channel(11, frequency=904500000, dr_min=0, dr_max=3)
lora.add_channel(12, frequency=904700000, dr_min=0, dr_max=3)
lora.add_channel(13, frequency=904900000, dr_min=0, dr_max=3)
lora.add_channel(14, frequency=905100000, dr_min=0, dr_max=3)
lora.add_channel(15, frequency=905300000, dr_min=0, dr_max=3)
lora.add_channel(65, frequency=904600000, dr_min=4, dr_max=4) # 500KHz uplink larger dr breaks(?)