|
| 1 | +package region |
| 2 | + |
| 3 | +import "tinygo.org/x/drivers/lora" |
| 4 | + |
| 5 | +const ( |
| 6 | + US915_DEFAULT_PREAMBLE_LEN = 8 |
| 7 | + US915_DEFAULT_TX_POWER_DBM = 20 |
| 8 | + US915_FREQUENCY_INCREMENT_DR_0 = 200000 // only for 125 kHz Bandwidth |
| 9 | + US915_FREQUENCY_INCREMENT_DR_4 = 1600000 // only for 500 kHz Bandwidth |
| 10 | +) |
| 11 | + |
| 12 | +type ChannelUS struct { |
| 13 | + frequency uint32 |
| 14 | + bandwidth uint8 |
| 15 | + spreadingFactor uint8 |
| 16 | + codingRate uint8 |
| 17 | + preambleLength uint16 |
| 18 | + txPowerDBm int8 |
| 19 | +} |
| 20 | + |
| 21 | +// Getter functions |
| 22 | +func (c *ChannelUS) Frequency() uint32 { return c.frequency } |
| 23 | +func (c *ChannelUS) Bandwidth() uint8 { return c.bandwidth } |
| 24 | +func (c *ChannelUS) SpreadingFactor() uint8 { return c.spreadingFactor } |
| 25 | +func (c *ChannelUS) CodingRate() uint8 { return c.codingRate } |
| 26 | +func (c *ChannelUS) PreambleLength() uint16 { return c.preambleLength } |
| 27 | +func (c *ChannelUS) TxPowerDBm() int8 { return c.txPowerDBm } |
| 28 | + |
| 29 | +func (c *ChannelUS) Next() bool { |
| 30 | + switch c.Bandwidth() { |
| 31 | + case lora.Bandwidth_125_0: |
| 32 | + freq, ok := stepFrequency125(c.frequency) |
| 33 | + if ok { |
| 34 | + c.frequency = freq |
| 35 | + return true |
| 36 | + } else { |
| 37 | + c.frequency = lora.Mhz_903_0 |
| 38 | + return true |
| 39 | + } |
| 40 | + case lora.Bandwidth_500_0: |
| 41 | + freq, ok := stepFrequency500(c.frequency) |
| 42 | + if ok { |
| 43 | + c.frequency = freq |
| 44 | + return true |
| 45 | + } else { |
| 46 | + return false |
| 47 | + } |
| 48 | + } |
| 49 | + |
| 50 | + return false |
| 51 | +} |
| 52 | + |
| 53 | +func stepFrequency125(freq uint32) (uint32, bool) { |
| 54 | + f := freq + US915_FREQUENCY_INCREMENT_DR_0 |
| 55 | + if f >= lora.MHZ_915_0 { |
| 56 | + return 0, false |
| 57 | + } |
| 58 | + |
| 59 | + return f, true |
| 60 | +} |
| 61 | + |
| 62 | +func stepFrequency500(freq uint32) (uint32, bool) { |
| 63 | + f := freq + US915_FREQUENCY_INCREMENT_DR_4 |
| 64 | + if f >= lora.MHZ_915_0 { |
| 65 | + return 0, false |
| 66 | + } |
| 67 | + |
| 68 | + return f, true |
| 69 | +} |
| 70 | + |
| 71 | +type RegionSettingsUS915 struct { |
| 72 | + joinRequestChannel *ChannelUS |
| 73 | + joinAcceptChannel *ChannelUS |
| 74 | + uplinkChannel *ChannelUS |
| 75 | +} |
| 76 | + |
| 77 | +func US915() *RegionSettingsUS915 { |
| 78 | + return &RegionSettingsUS915{ |
| 79 | + joinRequestChannel: &ChannelUS{lora.MHz_902_3, |
| 80 | + lora.Bandwidth_125_0, |
| 81 | + lora.SpreadingFactor10, |
| 82 | + lora.CodingRate4_5, |
| 83 | + US915_DEFAULT_PREAMBLE_LEN, |
| 84 | + US915_DEFAULT_TX_POWER_DBM}, |
| 85 | + joinAcceptChannel: &ChannelUS{0, |
| 86 | + lora.Bandwidth_500_0, |
| 87 | + lora.SpreadingFactor9, |
| 88 | + lora.CodingRate4_5, |
| 89 | + US915_DEFAULT_PREAMBLE_LEN, |
| 90 | + US915_DEFAULT_TX_POWER_DBM}, |
| 91 | + uplinkChannel: &ChannelUS{lora.Mhz_903_0, |
| 92 | + lora.Bandwidth_500_0, |
| 93 | + lora.SpreadingFactor9, |
| 94 | + lora.CodingRate4_5, |
| 95 | + US915_DEFAULT_PREAMBLE_LEN, |
| 96 | + US915_DEFAULT_TX_POWER_DBM}, |
| 97 | + } |
| 98 | +} |
| 99 | + |
| 100 | +func (r *RegionSettingsUS915) JoinRequestChannel() Channel { |
| 101 | + return r.joinRequestChannel |
| 102 | +} |
| 103 | + |
| 104 | +func (r *RegionSettingsUS915) JoinAcceptChannel() Channel { |
| 105 | + return r.joinAcceptChannel |
| 106 | +} |
| 107 | + |
| 108 | +func (r *RegionSettingsUS915) UplinkChannel() Channel { |
| 109 | + return r.uplinkChannel |
| 110 | +} |
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