0,0 → 1,226 |
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
// This code has been derived from the implementation of Stefan Engelke. |
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
/* |
Copyright (c) 2008 Stefan Engelke <stefan@tinkerer.eu> |
|
Permission is hereby granted, free of charge, to any person |
obtaining a copy of this software and associated documentation |
files (the "Software"), to deal in the Software without |
restriction, including without limitation the rights to use, copy, |
modify, merge, publish, distribute, sublicense, and/or sell copies |
of the Software, and to permit persons to whom the Software is |
furnished to do so, subject to the following conditions: |
|
The above copyright notice and this permission notice shall be |
included in all copies or substantial portions of the Software. |
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT |
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
DEALINGS IN THE SOFTWARE. |
|
$Id: rcdsl.c 60 2008-08-21 07:50:48Z taser $ |
|
RCDSL.H and RCDSL.C is an INOFFICIAL implementation of the |
communication protocol used by DSL receivers of Act Europe. |
The DSL receivers have a serial communication port to connect |
two receivers in diversity mode. Each receiver is sending the |
received servo signals periodically over this port. This fact |
can be used to connect the receiver to the control unit of the |
model via UART instead of evaluating the PPM signal. |
|
If you have any questions, fell free to send me an e-mail. |
|
*/ |
|
|
/* |
Connection of DSL to SV1 of FC: |
( DSL Pin1 is on side of channel 4 ) |
|
1. GND <--> pin 7 (GND) |
2. TXD <--> pin 3 (RXD1 Atmega644p) |
3. RXD <--> pin 4 (TXD1 Atmega644p) optional |
4. 5V <--> pin 2 (5V) |
|
Do not connect the receiver via PPM-Sumsignal output the same time. |
|
Data are send at every 20 ms @ 38400 Baud 8-N-1 |
|
Data Frame: |0xFF|0xFF|0x1F|FREQALLOC|??|RSSI|VBAT|??|CRC|10|CH0D1|CH0D0|CH1D1|CH1D0|CRC| ...etc |
|
FREQALLOC = 35, 40, 72 |
RSSI = 0.. 255 // Received signal strength indicator |
VBAT = 0...255 // supply voltage (0.0V.. 7.8V) |
|
Servo Pair: |0x1X|CHXD1|CHXD0|CHX+1D1|CHX+1D0|CRC| |
X is channel index of 1 servo value |
D1D0 is servo value as u16 in range of 7373 (1ms) to 14745 (2ms) |
there are 8 channels submitted, i.e 4 servo pairs |
|
|
Frame examples with signel received |
|
FFFF 1F23F079A304AD 1036012B1E6F 122AFB2AECB2 142B4D2B4404 1636872B33CE |
FFFF 1F23F079A304AD 1036002B1F6F 122AFE2AEBB0 142B4B2B4406 1636872B33CE |
FFFF 1F23F079A304AD 1035FF2B226E 122AFC2AEAB3 142B4E2B4304 1636882B33CD |
FFFF 1F23F079A304AD 1036022B1E6E 122AFB2AEEB0 142B4A2B4506 1636872B33CE |
FFFF 1F23F079A304AD 1036022B1E6E 122AFE2AEBB0 142B4B2B4406 1636882B33CD |
FFFF 1F23F079A304AD 1036012B1E6F 122AFD2AEAB2 142B4E2B4403 1636862B33CF |
FFFF 1F23F079A304AD 1036032B1D6E 122AFD2AEBB1 142B4C2B4504 1636862B33CF |
|
Frame examples with no signal received |
|
FFFF 1F23F000A30426 |
FFFF 1F23F000A30426 |
FFFF 1F23F000A30426 |
FFFF 1F23F000A30426 |
FFFF 1F23F000A30426 |
FFFF 1F23F000A30426 |
FFFF 1F23F000A30426 |
*/ |
|
#include <stdlib.h> |
#include "dsl.h" |
#include "rc.h" |
#include "uart0.h" |
|
uint8_t dsl_RSSI = 0; |
uint8_t dsl_Battery = 0; |
uint8_t dsl_Allocation = 0; |
uint8_t PacketBuffer[6]; |
uint8_t Jitter = 0; // same measurement as RC_Quality in rc.c |
|
typedef union |
{ |
int16_t Servo[2]; |
uint8_t byte[4]; |
} ChannelPair_t; |
|
ChannelPair_t ChannelPair; |
|
|
// This function is called, when a new servo signal is properly received. |
// Parameters: servo - servo number (0-9) |
// signal - servo signal between 7373 (1ms) and 14745 (2ms) |
void dsl_new_signal(uint8_t channel, int16_t signal) |
{ |
int16_t tmp; |
uint8_t index = channel + 1; // mk channels start with 1 |
|
RC_Quality = (212 * (uint16_t)dsl_RSSI) / 128; // have to be scaled approx. by a factor of 1.66 to get 200 at full level |
if(RC_Quality > 255) RC_Quality = 255; |
|
// signal from DSL-receiver is between 7373 (1ms) und 14745 (2ms). |
signal-= 11059; // shift to neutral |
signal/= 24; // scale to mk rc resolution |
|
if(abs(signal-PPM_in[index]) < 6) |
{ |
if(Jitter < 200) Jitter +=10; |
else Jitter = 200; |
} |
|
// calculate exponential history for signal |
tmp = (3 * (PPM_in[index]) + signal) / 4; |
if(tmp > signal+1) tmp--; else |
if(tmp < signal-1) tmp++; |
// calculate signal difference on good signal level |
if(Jitter >= 195) PPM_diff[index] = ((tmp - PPM_in[index]) / 3) * 3; // cut off lower 3 bit for noise reduction |
else PPM_diff[index] = 0; |
PPM_in[index] = tmp; // update channel value |
|
if(index == 4) |
{ |
NewPpmData = 0; |
} |
} |
|
// This function is called within dsl_parser(), when a complete |
// data packet with valid checksum has been received. |
void dsl_decode_packet(void) |
{ |
uint8_t i; |
|
// check for header condition |
if((PacketBuffer[0] & 0xF0) == 0x10) |
{ |
if(PacketBuffer[0] == 0x1F) // separate status frame |
{ |
dsl_Allocation = PacketBuffer[1]; // Get frequency allocation |
// ?? = PacketBuffer[2]; |
dsl_RSSI = PacketBuffer[3]; // Get signal quality |
dsl_Battery = PacketBuffer[4]; // Get voltage of battery supply |
// ?? = PacketBuffer[5]; |
if(dsl_RSSI == 0) |
{ |
for (i = 0; i<5; i++) |
{ |
PPM_diff[i] = 0; |
PPM_in[i] = 0; |
} |
} |
} |
else // probably a channel pair |
{ |
i = PacketBuffer[0] & 0x0F; // last 4 bits of the header indicates the channel pair |
if(i < 10)// maximum 12 channels |
{ |
// big to little endian |
ChannelPair.byte[1] = PacketBuffer[1]; |
ChannelPair.byte[0] = PacketBuffer[2]; |
ChannelPair.byte[3] = PacketBuffer[3]; |
ChannelPair.byte[2] = PacketBuffer[4]; |
dsl_new_signal(i, ChannelPair.Servo[0]); |
dsl_new_signal(i+1,ChannelPair.Servo[1]); |
} |
} |
} // EOF header condition |
} |
|
|
// this function should be called within the UART RX ISR |
void dsl_parser(uint8_t c) |
{ |
static uint8_t last_c = 0; |
static uint8_t crc = 0; |
static uint8_t cnt = 0; |
static uint8_t packet_len = 0; |
|
// check for sync condition |
if ((c==0xFF) && (last_c==0xFF)) |
{ |
cnt = 0; // reset byte counter |
crc = 0; // reset checksum |
return; |
} |
|
if(cnt == 0) // begin of a packet |
{ |
if(c == 0x1F) packet_len = 5; // a status packet has 5 bytes + crc |
else packet_len = 4; // a channel pair packet has 4 bytes + crc |
} |
if(cnt > packet_len) // packet complete, crc byte received |
{ |
// calculate checksum |
crc = ~crc; |
if (crc == 0xFF) crc = 0xFE; |
// if crc matches decode the packet |
if (c == crc) dsl_decode_packet(); |
// handle next packet |
cnt = 0; |
crc = 0; |
} |
else // collect channel data bytes |
{ |
PacketBuffer[cnt++] = c; |
crc += c; |
} |
// store last byte for sync check |
last_c = c; |
} |