Archives: Release

power_dist r4.5b

Here is yet another new product announcement! In the same line as the new pi3hat, here is a new minor revision of the power_dist, the r4.5b:

The changes are largely the same as for the new pi3hat:

  • The input voltage range is extended from 10-44V, to 10-54V [EDIT 2024-05-24: derated back to 44V].

  • The CAN-FD port has +-58V bus fault protection, up from +-12V.

  • Additionally, the measurement noise of the output current has been improved from 300mA to approximately 30mA.

moteus-n1 beta release

Implied by my previous writeup on pin selection for external connectors, we’ve got a new variant of the moteus controller to announce today in beta form, the moteus-n1!

This variant is intended to be more feature-full, higher performance (and higher cost). Here are some bullet points of the biggest differentiators with r4.11:

moteus n1 moteus r4.11
Price $159 USD @ qty 1 $104 USD @ qty 1
Size As small as 46mmx46mmx8mm with optional back connectors omitted. 58% of the volume, 87% of the top down footprint size of r4.11 53x46x12mm
External Peripherals Each of the auxiliary connectors supports SPI, UART, ADC, SW & HW Quadrature, Hall sensors, and I2C. 5V and 3.3V is provided on each connector to power peripherals (100mA for each voltage available combined between both connectors). I2C pullups are configurable on each connector. All 4 pins on AUX2 are 5VT, the two non-SPI pins on AUX1 are 5VT. ENC (AUX1) supports SPI, Hall and ADC. ABS (AUX2) supports UART and I2C and are both 5VT.
RS422 Built in RS422 transceiver for communicating with RS422 / BiSS-C encoders (BiSS-C / SSI not yet supported in software). None
Voltage 8-54V, 48V nominal 8-44V
Peak Output 100A output phase current, 1200W 100A output phase current, 500W
Continuous Output 9A output phase current ambient, 18A w/ thermal management 11A output phase current ambient, 22A w/ thermal management
CAN fault tolerance 58V bus fault tolerance 12V bus fault tolerance
Power Connectors Solder pads for DC bus input, one always present XT30, one optional XT30 2x XT30

The short form is that the n1 does not really expand the set of motors that can be usefully driven, but does enable operation in 48V systems, is more compact and electrically robust and provides significantly improved external peripheral support.

pi3hat r4.5

I’m excited to announce a minor upgrade to the mjbots pi3hat product line, the pi3hat r4.5!

This has a few upgrades over the old r4.4b:

  • The input voltage range is expanded from 8-44V to 8-54V.

  • All CAN-FD ports have +-58V bus fault protection, up from +-12V.

  • 0.1" pin headers are present for the Raspberry Pi I2C, UART, and for 3.3V and 5V outputs

Check it out at mjbots.com today!

moteus firmware 2023-02-01

Partly to celebrate moteus controllers being back in stock and partly because a lot of important work has backed up, we’ve just released a new firmware version for moteus (2023-02-01) that has a little bit of something for everyone. Future posts will examine some of these features in more detail, but for now you just get the bullet list:

  • Support sending and receiving arbitrary data from a UART configured on either of the auxiliary ports

moteus firmware release 2022-07-11

It has been on github for a few days now, but I’m excited to announce the newest moteus firmware release, 2022-07-11. This release includes some big features, and some quality of life improvements all around.

  • Flexible I/O subsystem: This release includes the new flexible I/O subsystem. This adds support for many new encoder types and lets you connect them up in a wide variety of ways.
  • Cogging torque compensation: Preliminary support for cogging torque compensation is present in this release. It works pretty well on a number of motor types already, future articles will describe it in more detail.
  • Encoder eccentricity compensation: This feature lets you linearize the output position and velocity in the face of non-linear encoder readings. A write-up for it is also forthcoming in the not-too-distant-future.
  • Transparent no-BRS CAN-FD communication: If your CAN-FD network is only capable of operating at 1Mbps, and you send queries frames with BRS turned off, moteus will now respond in kind. This eliminates most needs to change the CAN bus frequency due to marginal electrical properties.

This is an exciting time for moteus, and the new features will keep coming!

New moteus firmware release, 0.1-20200822-1

I’ve posted a new release of the firmware for the moteus brushless controller to github!

This release has a number of minor improvements in the host tools (for which there continue to be no distributed binaries, you get to build from source). The biggest improvement in the firmware is the improved low-torque operation as documented here and here. If you have any questions or want help upgrading, hop into discord at #moteus and ask!