From 3b5d2b6a167531afe2d385c5abb364d86187ac47 Mon Sep 17 00:00:00 2001 From: Nicholas Sherlock Date: Sat, 7 Mar 2015 13:07:03 +1300 Subject: [PATCH] Change recommended Blackbox baudrate to 250000 This is because the AVR's 230400 baudrate is very inaccurate, while the 250000 baudrate is spot-on. --- docs/Blackbox.md | 8 ++++---- src/main/blackbox/blackbox_io.c | 6 +++--- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/docs/Blackbox.md b/docs/Blackbox.md index 05462bf0e..2c4bbd38b 100644 --- a/docs/Blackbox.md +++ b/docs/Blackbox.md @@ -43,7 +43,7 @@ software was developed on a craft with a looptime of 2400. Any looptime smaller data rate. The default looptime on Cleanflight is 3500. If you're using a looptime of 2300 or smaller, you will probably need to reduce the sampling rate in the Blackbox -settings, or increase your logger's baudrate to 230400. See the later section on configuring the Blackbox feature for +settings, or increase your logger's baudrate to 250000. See the later section on configuring the Blackbox feature for details. ## Hardware @@ -59,7 +59,7 @@ it should be reflashed with the [OpenLog Light firmware][] or the special [OpenL be version 2.0 or higher to allow configuration of baud rates). The Blackbox variant of the firmware ensures that the OpenLog is using the correct settings, and defaults to 115200 -baud. If you are using a looptime of 2500 or smaller, you should set the baud rate to 230400 instead to eliminate +baud. If you are using a looptime of 2500 or smaller, you should set the baud rate to 250000 instead to eliminate dropped frames. You can find the Blackbox version of the OpenLog firmware [here](https://github.com/cleanflight/blackbox-firmware), @@ -96,7 +96,7 @@ the best chance of writing at high speed. You must format it with either FAT, or Power up the OpenLog with a microSD card inside, wait 10 seconds or so, then power it down and plug the microSD card into your computer. You should find a "CONFIG.TXT" file on the card. You should see the baud rate that the OpenLog has -been configured to. You probably want this to be set to either 115200 (the default) or 230400 (for craft with looptimes +been configured to. You probably want this to be set to either 115200 (the default) or 250000 (for craft with looptimes smaller than 2500). Save the file and put the card back into your OpenLog, it should use those settings from now on. @@ -158,7 +158,7 @@ Enter `set blackbox_device=1` to switch to logging to an onboard dataflash chip, ## Configuring the Blackbox -If you are using a short looptime like 2500 or smaller, try switching your OpenLog to 230400 baud (instead of the +If you are using a short looptime like 2500 or smaller, try switching your OpenLog to 250000 baud (instead of the default of 115200) and set that baud rate on the Blackbox's port in the Confgurator. The Blackbox currently provides two settings (`blackbox_rate_num` and `blackbox_rate_denom`) that allow you to control diff --git a/src/main/blackbox/blackbox_io.c b/src/main/blackbox/blackbox_io.c index b54bcf5c9..835777725 100644 --- a/src/main/blackbox/blackbox_io.c +++ b/src/main/blackbox/blackbox_io.c @@ -456,10 +456,10 @@ bool blackboxDeviceOpen(void) portMode = MODE_TX; - if (baudRates[baudRateIndex] > 115200) { + if (baudRates[baudRateIndex] == 230400) { /* - * OpenLog can't keep up faster baud rates without giving it a larger inter-character gap to - * work with. + * OpenLog's 230400 baud rate is very inaccurate, so it requires a larger inter-character gap in + * order to maintain synchronization. */ portMode |= MODE_STOPBITS2; }