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Fix bus power problems in onewire 

See #676

The 1-wire pin was being set back to output low, which reset all 1-wire
devices on the bus.

Change the power == 0 behaviour to tri-state the pin, as I believe was
intended. Make this not the default, because the bus should be high
when a bit/byte is not being read/written. A low bus for a long time
is a reset condition.

Signed-off-by: Nick Andrew <nick@nick-andrew.net>
This commit is contained in:
Nick Andrew 2015-10-04 17:25:11 +11:00
parent bb9dd62882
commit 5dee9d03fb
1 changed files with 9 additions and 12 deletions
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19
app/driver/onewire.c
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@ -74,7 +74,6 @@ static uint8_t LastDeviceFlag[NUM_OW];
void onewire_init(uint8_t pin)
{
// pinMode(pin, INPUT);
platform_gpio_mode(pin, PLATFORM_GPIO_INPUT, PLATFORM_GPIO_PULLUP);
#if ONEWIRE_SEARCH
onewire_reset_search(pin);
@ -176,8 +175,7 @@ void onewire_write(uint8_t pin, uint8_t v, uint8_t power /* = 0 */) {
}
if ( !power) {
noInterrupts();
DIRECT_MODE_INPUT(pin);
DIRECT_WRITE_LOW(pin);
platform_gpio_mode(pin, PLATFORM_GPIO_INPUT, PLATFORM_GPIO_FLOAT);
interrupts();
}
}
@ -185,11 +183,10 @@ void onewire_write(uint8_t pin, uint8_t v, uint8_t power /* = 0 */) {
void onewire_write_bytes(uint8_t pin, const uint8_t *buf, uint16_t count, bool power /* = 0 */) {
uint16_t i;
for (i = 0 ; i < count ; i++)
onewire_write(pin, buf[i], 0);
onewire_write(pin, buf[i], 1);
if (!power) {
noInterrupts();
DIRECT_MODE_INPUT(pin);
DIRECT_WRITE_LOW(pin);
platform_gpio_mode(pin, PLATFORM_GPIO_INPUT, PLATFORM_GPIO_FLOAT);
interrupts();
}
}
@ -220,9 +217,9 @@ void onewire_select(uint8_t pin, const uint8_t rom[8])
{
uint8_t i;
onewire_write(pin, 0x55, 0); // Choose ROM
onewire_write(pin, 0x55, 1); // Choose ROM
for (i = 0; i < 8; i++) onewire_write(pin, rom[i], 0);
for (i = 0; i < 8; i++) onewire_write(pin, rom[i], 1);
}
//
@ -230,13 +227,13 @@ void onewire_select(uint8_t pin, const uint8_t rom[8])
//
void onewire_skip(uint8_t pin)
{
onewire_write(pin, 0xCC, 0); // Skip ROM
onewire_write(pin, 0xCC, 1); // Skip ROM
}
void onewire_depower(uint8_t pin)
{
noInterrupts();
DIRECT_MODE_INPUT(pin);
platform_gpio_mode(pin, PLATFORM_GPIO_INPUT, PLATFORM_GPIO_FLOAT);
interrupts();
}
@ -319,7 +316,7 @@ uint8_t onewire_search(uint8_t pin, uint8_t *newAddr)
}
// issue the search command
onewire_write(pin, 0xF0, 0);
onewire_write(pin, 0xF0, 1);
// loop to do the search
do