Commit Graph

4 Commits

Author SHA1 Message Date
Kevin O'Connor 0cbb8fdc9a lcd_st7920: Only calibrate wait ticks on mcus with strict timing
The calibration isn't valid on the linux mcu, so make it dependent on
CONFIG_HAVE_STRICT_TIMING.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
2020-05-31 14:57:06 -04:00
Kevin O'Connor effe6f6ddd lcd_st7920: Add brief delay around gpio toggle calls on fast MCUs
On fast MCUs (like the SAMD51) it is possible for the gpio to toggle
faster than the st7920 can accept.  Add a small delay around the clock
rise signal.

Signed-off-by: Lars R. Hansen <popshansen@hotmail.com>
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
2019-08-10 11:45:15 -04:00
Kevin O'Connor f08a0c5e93 lcd_st7920: Use a longer delay at the start of each command/data
It appears the st7920 requires a longer delay when switching from
command to data mode (and vice-versa).  Slower MCUs don't show a
problem because the klipper command processing time results in a
sufficient delay.  However, some of the faster MCUs can process
klipper commands fast enough that the next st7920 transfer is sent too
fast.  Add an additional delay to account for this.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
2018-06-22 23:47:09 -04:00
Kevin O'Connor 9140f36d99 lcd_st7920: Add micro-controller code for the ST7920 LCD chip
Add support for passing messages to an ST7920 chip via a SPI
bit-banging interface.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
2018-03-06 11:30:30 -05:00