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HEQ-5/6 Update Kit V4.17D

Click to enlarge

Click to enlarge

The HEQ-5/6 MCU Update kit for all Syntha (Skywatcher) Atlas/HEQ-5/EQ-6/Atlas Mounts opens new possibilities. It is applicable with the new and old (without Rev. switches in the Hand controller) Mount. The HEQ-5/6 MCU Update kit repairs the main problems (microstepping, Autoguiding interface, smallest correction speed of 2x, PC connection, Transmission play, PEC) of the original control without replacement the original controller, like it is necessary with the EQ6 Booster. Only a small module will be placed in the original control and then there are some features, which are missing with the original control. The HEQ-5/6 MCU update closes the gap between the ext. Autoguiding Interface and the EQ6 Booster. By the use of the LX200 Protocol innumerable free programs are available, which make the binding to the PC possible and easy. These LX200 commands are supported (#:MS# only with GOTO option).

Some features:

  • Microstepping operation in RA and DEC
  • GOTO (speed 20x - 100x) over the LX200 protocol (optional)
  • Intelligent Tracking with IntellyTrack® (optional)
  • Autoguidinginterface (ST-4 compatible)
  • RS232 (LX200) Autoguiding-Interface
  • Supporting the LX200 PulseGuide Commands
  • 3 speeds (Siderial/Solar/Lunar)
  • Correction speed smaller then 2x can be configured
  • Support of the Conrad Gearbox Project
  • Backlash compensation in RA and DEC
  • PEC (periodic error correction) with 256 Measurepoints
  • Speeds (2x,8x,16x) are configurable freely (1,3x - 40x)
  • Support of the LX200 focus commands
  • Focus control with the original Handbox (optional)
  • DSLR Control Support for Canon DSLR's
  • LX200 Fan control support
  • Firmware updates send over the serial interface
  • Re-Programmable through out led programming interface
  • Support for the LittleFoot Display Project

For the update kit are no modifications to the controller or the hand controller box necessary. Only a small cutout for the connector socket must be filed into the cover. The installation can be done by everyone! The old processor (it is in a socket) must be pulled out and the HEQ-5/6 MCU Update kit will placed in the now free socket.

The basic configuration in the interface is so adjusted that the function remains like it is known. Only the microstepping operation and the reduced correction speed in the Autoguiding mode let suspect that another control serves the work. Those using the Conrad gear must configure this with the Updateprogramm, since otherwise the adjusting speed is too fast with 132:1.

To adjust the parameters I wrote a small Tool that can be downloaded in the Software section. The gear transmission configuration becomes only active after turning the Mount off and on!
The Configuration over the hand controller is described here.

Recommended accessories:

  1. Adapter cable 5m serial (RS232) 9 pole
  2. Adapter cable 1,5m ST-4 compatibly 15 pole
  3. Code to enable IntellyTrack®
  4. Code to enable GOTO
  5. HEQ-5/6 Hand controller Update
    (There are two kind of Handcontrollers outside.
    If you order the Handbox update, i have to know
    if the Handbox has two Rev. Switches on the right side!
  6. Conrad Gears (100:1 for RA and DEC)

Here the guidance for the installation, that also has the connection diagram for the connector ;-)

For Kits and ready made MCU Updates check out the Astromarket!


Software and Info for the HEQ-5/6 MCU Update kit:

V4 Control from Doug Dieter (Win32)

MCU Configure from Rick Saunders (Linux)

Aspect from Wolfgang Hoffmann (Win32, Linux)

HEQ-5/6 MCU Update V3.40 (Win32)

HEQ-5/6 MCU Update V3.40 (PocketPC)

HEQ-5/6 MCU Update from Stefan (Linux)

HEQ-5/6 PEC Explorer V1.30 (Win32)

LX200 Tester V1.00 (Win32)

LX200 Tester from Stefan (Linux)

PocketGuider for PocketPC :-)

HEQ-5/6 MCU Update Kit (PDF)


HEQ-5/6 MCU Upgrade Yahoo Group

HEQ-5/6 MCU Update Support-Forum


Building guidance for the self construction:

The self construction kit consists of the circuit PCB board, the programed processor and all other parts required for the update. Also a printed drilling template is attached to each kit.

Click to enlarge

The constrution is not a large thing, but one should be able to deal with a soldering iron. There is no programming knowledge required and also a special programmer is not needed, since the processor is already programmed and all parameters can be configurated over the serial interface!

Schematic diagram
Bill of material

At the beginning the Parts at the bottom of the PCB should be soldered. These are the Parts R1, D1 and D2. Here watch the length of the legs on the top side. The remaining legs has to be cut very short, because if they are to long, the MCU will not sit correct at the surface!

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Click to enlarge

As second step I suggest, to solder the adapter for the original processor socket. Since the place between the socket and the plate is very small, the update kit must be placed as flat as possible, I used a small trick here. The two 20pol. strips are put from the top into the pcb. Here on the fact it respects that the longer ends must be put into the plate. Now the pins are soldered from down side. Here be very economically with tin solder ; -)

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Click to enlarge

If the pins are firmly soldered, remove the black spacers with a small screwdriver from the pins. Now the supernatant pins can be cut off and we have a flat adapter for the processor socket.

Click to enlarge

Click to enlarge

The remaining construction units can be equipped simply after bill of material. In the HEQ-5 Update kit the connector is not mounted directly on the PCB. Here it is connected throw a flat cable. Keep a eye on that the Goldcap for the EQ-6 is soldered to the pads GC1 while GC2 is used for the HEQ-5. The polarity is written on the PCB.
So far if everything is correct, the interface can be inserted as described in the guidance for the installation.

Click to enlarge


Guidance for the installation:

Guidance for the HEQ-5

Guidance for the Atlas/EQ-6


Handbox Update:

In order to be able to configure and control parts of the new functionality with the original hand controller, i also reprogrammed the processor in the handbox . The voltage monitor of the old Handbox remains natural ; -)

I tried to avoid the green LED and like that this LED is only active in the PEC training.

The new LED color conditions:

Red on = PEC active

Red off = PEC deactivated

Orange on = Key pressed

Orange blinking = depending upon frequency, menu or voltage monitor

Green blinking 10s = PEC Training begins

Green on = PEC Training running

The software in the handpaddle has now 3 menus. These can be activated over the switch (2x = menu 1, 8x = menu 2, 16x = menu 3) and the simultaneous press of all four direction keys. The LED flashes then 1x, 2x or 3x briefly. In the menu the direction keys have the following meaning:

Menu 1:

Left = Focus (-)

Right = Focus (+)

Up = Toggle 2x <=> 1.3x

Down = Find Object (see Update Kit Protocoll)

Menu 2:

Left = speed Lunar

Up = speed Siderial

Right = speed Solar

Down = no tracking (terrestial)

Menu 3:

Left = PEC off

Up = Start/Stop PEC Training

Right = PEC on

Down = Invert GOTO DEC direction

The HEQ-5/6 key exchange was also implemented again. If both RA or DEC keys are pressed at the same time, the direction keys are exchanged. The small tiny switches on the right side of the new handbox have thus for the time being retired :-)


Connection allocation of the connetor plug:

connection pin


Zeromodem 9pol.


Focus (+) +5V



TxD (Rs232)



RxD (RS232)






CPU (MOSI) + Focus Speed



CPU (MISO) + Fan control



CPU (SCK) + User defined



CPU (Reset)






(ST-4 compatible) UP



(ST-4 compatible) DOWN



(ST-4 compatible) RIGHT



(ST-4 compatible) LEFT



User defined (see Supportforum)



Focus (-) +5V


Too good lastly still the sayings, without which it unfortunately sometimes comes in our constitutional state to misunderstandings:
The structural drawings veroeffenlichten by me, plates etc. are freely reproductionable for private users. A commercial marketing of devices to these structural drawings to attribute are, is permitted only with expressly written permission. Reproduction and application to own danger. For function and/or for possible damage, which due to reproductions, which from me publish structural drawings, plates etc. result in, I do not take over myself any responsibility! That sounds itself badly, is however half so wild (with me everything functions perfectly). I have only no desire me for a damage to answer for, only because someone has from such things no notion, a Akku short circuit and the hut or other absengelt.

Copyright © 2004 by Anand Rajiva , E-Mail: MCU.Update@rajiva.de