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.

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!

Here’s yet another update to the moteus line, moteus r4.11!

r4.11 is electrically, mechanically, and software compatible with r4.3, r4.5, and r4.8.

This revision supports two alternate footprints for the CAN-FD transceiver to better support component availability and refines the power stage for the DRV8353 gate driver. moteus r4.8 was the first version to use the DRV8353 because of, once again, component availability issues. However, it was developed on a very abbreviated schedule. With r4.11 the EMI is much improved over r4.8 and r4.5, and the efficiency is much better than r4.8 at all input voltages and PWM frequencies.

I’m excited to announce the release of moteus r4.8!

Due to the ongoing semiconductor apocalypse, this minor release uses some alternate components which were easier to source. It remains compatible with the r4.5 and r4.3 both electrically, mechanically, and with firmware.

For now, the biggest win is that the board and the devkit are actually in stock!

A secondary win is that external primary encoders are now supported, via an unpopulated connector pad on the backside of the board. I’ll write up more about that in a later post.

In what probably won’t be the last time, mjbots.com now has a new version of the pi3hat due solely to component shortages!

There are no top-level feature changes versus the previous r4.4. What is different is that the connector for the Raspberry Pi has reverted to the fixed height version that the r4.3 and earlier used, and the IMU is slightly better.

Happy building!

I’d like to introduce the newest mjbots product, an updated revision of the power_dist, 4.3b available at mjbots.com today!

This version has a number of improvements over the previously released r3.1:

	r4.3b	r3.1
Voltage Range	10-44V	8-34V
Maximum load capacitance	4,000 uF	400 uF
Quiescent Current	300uA	5mA
Current (Continuous / Peak)	45A / 80A	unrated / 100A
Energy Monitoring	YES	NO
Switch Mode	High Side	Low Side
Dimensions	50x80mm	45x70mm
Price	$139	$79

The only real downsides are that is more expensive and slightly larger.

mjbots.com had a week long run where we were completely out of fdcanusbs, which meant that we were also out of all development kits too. Well, a production run just came in:

So now we’ve got everything back in stock once again!

• fdcanusb
• moteus r4.5 development kit
• qdd100 beta 2 development kit

It seems like all the posts I’m writing these days are for new products! Here’s the pi3hat r4.4:

There are two changes from the previous r4.2. First, it now supports voltage inputs up to 44V. Second, in support of future upgrades, the 5th CAN-FD port has been upgraded to support 8Mbps, but downgraded to no longer have a wide common mode voltage range.

THUS, IT IS NOT SAFE TO CONNECT THE CAN-FD PORT ON THE pi3hat r4.4 TO A power_dist r3.X BOARD.

I’d like to introduce the qdd100 beta 2!

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This is the newest version of a quasi-direct-drive servo from mjbots. It has a sleek new look, and improved performance all around:

	Beta 1	Beta 2
Peak Torque	12.5 Nm	16 Nm
Backlash	+- 0.2 degrees	+- 0.1 degrees
Voltage Range	10-34V	10-44V
Mass	470g	475g

Comparison from beta 1 to the new beta 2

Additionally, the M3 mounting holes are now 3mm deep instead of the previous 2mm, which gives more flexibility when designing mounts.

Welcome to the newest mjbots.com product, the mj5208:

This is a high quality 5208 sized 330Kv wound brushless motor with short pigtails intended to connect to moteus controllers. All the moteus devkits as of last week are shipping using this motor instead of the previous “semi-random” motor.

Specifications:

• Peak torque: 1.7 Nm
• Mass (with wires): 193g
• Peak power: 600W
• Kv: 330
• Dimensions: 63x25mm

There are two bolt patterns on the output, a 3x M3 17mm diameter one, and a 2x M3 pattern spaced at 12mm. The stator side has a 4x M3 pattern spaced at 25mm radially and a 3x M2.5 spaced at 32mm. The axle protrudes a few mm from the stator, making it easy to adhere the diametric magnets needed for moteus.