# Bluejay [](https://github.com/mathiasvr/bluejay/releases/latest) [](https://discord.gg/phAmtxnMMN) Digital ESC firmware for controlling brushless motors in multirotors. > Based on [BLHeli_S](https://github.com/bitdump/BLHeli) revision 16.7 Bluejay aims to be an open source successor to BLHeli_S adding several improvements to ESCs with Busy Bee MCUs. ## Current Features - Digital signal protocol: DShot 150, 300 and 600 - Bidirectional DShot: RPM telemetry - Selectable PWM frequency: 24, 48 and 96 kHz - PWM dithering: 11-bit effective throttle resolution - Power configuration: Startup power and RPM protection - Numerous optimizations and bug fixes See the project [changelog](CHANGELOG.md) for a list of changes. ## Flashing ESCs Bluejay firmware can be flashed to BLHeli_S compatible ESCs and configured using any of the following: - [ESC Configurator](https://esc-configurator.com/) (PWA) - [Bluejay Configurator](https://github.com/mathiasvr/bluejay-configurator/releases) (Standalone) ### Release binaries All releases can be found in the [releases](https://github.com/mathiasvr/bluejay/releases) section. Release files use a naming convention similar to BLHeli: `{T}_{M}_{D}_{P}_{V}.hex`. | | | | |---|--------------------|---------------------------------------------------------| | T | `A` - `W` | Target ESC layout | | M | `L` or `H` | MCU type: `L` (BB1 24MHz), `H` (BB2 48MHz) | | D | `0` - `90` | Dead time (`0` *only* for ESCs with built-in dead time) | | P | `24`, `48` or `96` | PWM frequency [kHz] | | V | E.g. `0.7` | Bluejay version | ## Comparison of BLHeli_S and Bluejay settings The following table shows a correspondence between BLHeli_S and Bluejay's startup power settings. | BLHeli_S | Bluejay | | | |---------------|--------------------|--------------------|--------------------| | Startup Power | Min. Startup Power | Max. Startup Power | RPM Power (Rampup) | | 0.031 | 2 (1001) | 1 (1004) | 2x | | 0.047 | 4 (1002) | 2 (1008) | 2x | | 0.063 | 6 (1003) | 3 (1012) | 3x | | 0.094 | 8 (1004) | 4 (1016) | 4x | | 0.125 | 12 (1006) | 6 (1024) | 5x | | 0.188 | 18 (1009) | 9 (1035) | 6x | | 0.25 | 24 (1012) | 12 (1047) | 7x | | 0.38 | 36 (1018) | 18 (1071) | 8x | | 0.50 | 50 (1024) | 25 (1098) | 9x | | 0.75 | 74 (1036) | 37 (1145) | 10x | | 1.00 | 100 (1049) | 50 (1196) | 11x | | 1.25 | 124 (1061) | 62 (1243) | 12x | | 1.50 | 150 (1073) | 75 (1294) | 13x | - **Minimum startup power:** Minimum power when starting motors. Increase if motors are not able to start with low throttle input. - **Maximum startup power:** Limits power when starting motors or reversing direction. - **RPM Power Protection (Rampup):** Limits how fast power can be increased. Lower values will avoid power spikes but can also decrease acceleration. ## Contribute Any help you can provide is greatly appreciated! If you have problems, suggestions or other feedback you can open an [issue](https://github.com/mathiasvr/bluejay/issues). You can also join our [Discord server](https://discord.gg/phAmtxnMMN) to ask questions and discuss Bluejay! ### Obtaining the toolchain To obtain the toolchain, [download the C51 package from Keil](https://www.keil.com/demo/eval/c51.htm). Run it with wine: wine c51v960a.exe This will install toolchain and uVision. To obtain a license key (which you will need in order to link files above a certain size) you will have to run uVision in order to get your Computer ID. wine ~/.wine/drive_c/Keil_v5/UV4/UV4.exe Go to "File" -> "License Management" note your "Computer ID". With this information, you can request a licence key on the [Keil license installation page](https://www.keil.com/license/install.htm?P=X9F3Y-I8FIW-TWSZ0). In the CID field you need to enter the Computer ID which uVision showed you in the previous step. The license ID will be sent to you via E-Mail, once received you paste it into the LIC field, press "Add LIC" and you are done. ### Building For your convenience a Docker Image is provided that will set up the toolchain. For this to work you need to have completed the step [Registering via Wine](#registering-via-wine) and your ```.wine``` directory has to be copied to the tools directory. > The .wine directory can be deleted from the tools directory after the docker image has been created. To build the docker image [install docker](https://docs.docker.com/engine/install) and from the tools directory run: docker build -t bluejay-build . A build script is provided, it will build all targets if no further parameters are provided: ./build.sh or a specific target if you chose to: ./build.sh -l A -m H -d 0 -p 96 If a specific target is chosen, all parameters need to be provided: layout, mcu, deadtime and pwm The source from the projects root is used to build the firmware.