ESP32Focuser Hardware

This is a repository for storing documentation for my ESP32Focuser project.

Описание

Deutsche

What is that about

Focuser for astronomy telescope based on ESP32 controller. Comportable with Indilib (http:/indilib.org/) and ASCOM (https://ascom-standards.org/). The controller uses the protocol Moonlite (as documented in the indilib project).

What hardware do I need

The firmware runs on a ESP32-DevKitC board. It uses also the BIGTREETECH TMC2209 V1.2 Stepper Motor Driver to drive the motor on a super-silent and vibrationless way. Basically, you only need this two boards to start using the focuser. If you want to build it on a more resilient way, you can follow intructions below.

Schematics

Schematics diagram can be found as a KiCad project folder. You can donwload shematics as pdf here.

The schematics is pretty easy. You just connect the pins of the ESP32 dev board with the TMC2209 board, add power supply and connect motor - from this point you can control the focuser from the computer over ASCOM/INDI driver. If you want to use an optical encoder as a handcontroller (what I would really advise you if you want to get rid of vibrations when you touch the telescope focuser knob), connect it to the pins on the ESP32 board as well.

Wiring table

Please use the wiring table as reference, it might get outdated. For the most latest schematics version, check the KiCad project.

Description	ESP32 board	TMC2209 board	Note
DIR	32	DIR
STEP	33	STEP
CLK	25	CLK
PDN	26	PDN + PDN	not used
MS2	14	MS2
MS1	12	MS1
EN	13	EN
ENC1	2		Encoder output 1
ENC2	15		Encoder output 2
5V	5V	VDD
12V		VM	Motor power supply

Stepper motor

I use the 17HS2408 stepper motor, as it fits well for 12v supply: it has 8 Ohm phase resistance what leads to 1.5 Amps phase current, it's a bit over the specification (rated current 0.6 Amps) but as it's not supposed to continuously work on high speed in this project,it works just fine, has enough torque and does smooth movements.

BOM

Aka bill of material

Description	AliExpress link	Notes
ESP32-DevKitC	https://www.aliexpress.com/item/4000103411061.html
17HS2408 stepper motor	https://www.aliexpress.com/item/33033986185.html
7 M3 screws for motor and encoder	https://www.aliexpress.com/item/32965979997.html	M3 50pcs + 5mm
TMC2209 board	https://www.aliexpress.com/item/33029587820.html
Optical rotary encoder CALT ES38	https://www.aliexpress.com/item/33028641351.html	5v 600ppr
13x32mm Encoder knob	https://www.aliexpress.com/item/33039964137.html
Motor shaft coupler 5mm x ?? mm	https://www.aliexpress.com/item/32913158582.html
OR alternatively to the direct coupling your motor with the focuser, you could use a belt like this below
GT2 Pulley 20 tooth ø 5mm	https://www.aliexpress.com/item/32724156349.html
GT2 Closed Loop Timing Belt	https://www.aliexpress.com/item/32950422029.html
12v female plug 5.5mm x 2.1mm
12v→5v DC-DC step down converter board	https://www.aliexpress.com/item/32742116421.html
Hand controller connector M GX12 5 pin for encoder	https://www.aliexpress.com/item/32869491577.html
Hand controller connector M GX12 4 pin for motor	https://www.aliexpress.com/item/32869491577.html
115 90 55mm plastic enclosure case	https://www.aliexpress.com/item/32709832386.html
100x68x50mm plastic enclosure case for encoder	https://www.aliexpress.com/item/32792270384.html
Push button for handcontroller	https://www.aliexpress.com/item/32965284265.html
Micro USB cable	tbd
2.54mm Wire Cable Connector 4 pin	https://www.aliexpress.com/item/32954418743.html
Prototyping board 5x7 cm	https://www.aliexpress.com/item/32853911495.html
Cable for motor 4 cores 0.3mm 22awg	https://www.aliexpress.com/item/4000714461664.html

Pictures