AHP GT1 Parts list manual

AHP® GT1 Motor Controller
Manual and Usage Guide
Revision 1 – 2018/03/06
Ilia Platone – AHP®
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AHP® GT1 Motor Controller - Manual and Usage Guide
Table of contents
Chapter Page
1. G 1 specifications 3
2. he microstepping function 4
3. he S -4 or GPIO port 4
4. he connection to motors or actuators 5
5. he communication port 5
6. he configuration utility 6
1. Empty board – Bootloader update 6
2. Bootloader updated – Firmware loading 7
3. Failsafe mode – reset 8
4. Firmware configuration 9
1. Calculation of gear ratios 10
2. Mount types 10
3. Configuration profiles 11
7. Maximum speed vs. gear ratio 12
8. Damage & security prescriptions 12
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AHP® GT1 Motor Controller - Manual and Usage Guide
GT1 specifications
he G 1 is a stepper motor controller with goto functionality compatible on all
types of telescope mounts, being able to set the number of steps per worm and axis
revolution. he precision of microstep x64 allows precise goto and impeccable
sidereal tracking. Being compatible with the Syntha protocol, you can drive it with a
Synscan handset or directly with EQMOD, on Windows and on Linux.
It is also compatible with any type of motor and it is capable to supply up to 1A of
current for each winding. You can also wire the connected steppers in any way and
set a parameter from the configuration application to find the right combination,
without having to re-heat the connection wires.
It is equipped with these inputs / outputs:
1. Synscan-compatibile handset Input/Output
2. S 4 auto guider input
3. Stepper output for Right Ascension
4. Stepper output for Declination
5. 12v power supply input
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AHP® GT1 Motor Controller - Manual and Usage Guide
The microstepping function
When tracking in sidereal speed, and when moving at fine speed the mounting,
the controller enters microstepping mode. You can recognize this mode when you
hear an harmonic sound from the stepping motors. Microstepping mode is an
operational mode of moving motors capable to enter sub-step resolutions. he total
number of steps reached is then much higher this way and a greater resolution is
possible.
The ST- or GPIO port
he G 1 is equipped with an S -4 autoguider port, which can be customized
for specific functionalities like incremental encoder readings or to drive leds or other
peripherals. When updating the firmware, or when configuring the device, you can
choose how to use the GPIO port, if you desire the default S -4 function, or to
change its function, or else to not use it at all. See Illustration 1.
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Illustration 1: The pinouts of the GT1 connectors in their default configuration

AHP® GT1 Motor Controller - Manual and Usage Guide
The connection to motors or actuators
The GT1 is ca able to su ly 1A on 8 different lanes. Usually these out uts
are used for ste ing motors as in the default configuration, but we don’t exclude
future im rovements or configurations for different usage/motor or load ty es. The
default configuration ermits to connect and drive two ste er motors ranging from
12 to 24 volts su ly. The configuration utility ermits connecting the windings in
any order and a single arameter or setting ermits their correct usage and direction.
The communication port
The GT1 communicates with the driving PC application or the SynScan®
controller through the Communication port (or HC port). he communication
happens using a standard RS232 protocol running at 9600bps, one stop bit, no parity,
no flow control.
If the user prefers to not use a SynScan® controller, then there is the chance to
simulate its protocol and drive the G 1 from a Personal Computer or an SBC box.
he G 1 is compatible with EQAscom and INDI EQMod drivers for ASCOM and
INDI platforms respectively. It is not an aim of this document to specify the
characteristics of these software neither to explain the features of the SynScan
protocol.
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AHP® GT1 Motor Controller - Manual and Usage Guide
The configuration utility
AHP® offers a variety of software dedicated to Astronomy amateurs included
into a software suite named ADPA Suite. You can find more information about the
ADPA Software Suite at https://www.adpasuite.com.
ADPA includes a configuration utility for the G 1. With this application you
can flash both the bootloader and the firmware for the G 1, you can also configure it
to best suite into your mount configuration and you can test your settings in realtime.
Empty board – Bootloader update
he G 1 has the capability to upgrade its firmware using a dedicated
bootloader. You can at any time upgrade both the firmware and the bootloader, using
the communication port directly. If the firmware is not yet loaded, the bootloader
should be loaded and running. Select the serial port on which the G 1 is connected,
you can then see on the status bar of the Configuration utility the version of the
bootloader (if there is not any firmware loaded), or the version of the firmware. If you
wish to upgrade the bootloader, please choose from the “load firmware” button the
bootloader firmware upgrade (file starting with “G 1BOO _XXX”, where XXX is
the version). Once loaded, press “flash” to write the bootloader. When the
progressbar completes the upload a confirmation message (Success) should appear.
Keep much attention during this phase and ensure that the checksum of the firmware
is the same as the one reported into the website. After upgrading, confirm by pressing
the OK button and wait a minute, then select again the serial port where the G 1 is
connected. CAU ION: PLEASE DO NO UNPLUG HE CABLE OR POWER
DOWN HE DEVICE DURING HIS PROCESS! IF UNSUCCESSFUL
FLASHING HE DEVICE MAY NO WORK ANYMORE!
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AHP® GT1 Motor Controller - Manual and Usage Guide
Bootloader updated – Firmware loading
If the firmware is loaded, the firmware can be upgraded or installed. he
method is the same as the bootloader: open the firmware file using the “Load
Firmware” button (the firmware file starts with G 1FW_XXXX, where XXXX is the
firmware version). he firmware then can be upgraded/installed by clicking on the
“Flash” button. If the firmware is updated with success, then a confirmation dialog
will appear. After this step, please re-select the COM port on which the G 1 is
connected. he configuration Utility will say that the G 1 is ready to be configured.
CAU ION: PLEASE DO NO UNPLUG HE CABLE OR POWER DOWN HE
DEVICE DURING HE FLASHING PROCESS! IF UNSUCCESSFUL FLASHING
HE DEVICE MAY NO WORK ANYMORE!
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AHP® GT1 Motor Controller - Manual and Usage Guide
Failsafe mode – reset
If anything went wrong during the flash or upgrade process, there is the
possibility to reset the device at any time and start the bootloader. o do this you
should open the G 1 box and act on the circuit board. o do this please use much
attention, or you may cause irreversible damage to the device. Here the steps to do to
start the G 1 in fail-safe mode:
Unscrew the four screws on the bottom of the box
power up the G 1 with a 12v power supply
with a small wire connect the pin 1 and the pin 3, the pin 1 is the leftmost pin
when reading the string “ICSP” is on the top (see picture 2)
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AHP® GT1 Motor Controller - Manual and Usage Guide
Firmware configuration
he Firmware of the G 1 permits various configurations of gear ratios,
maximum speed allowed, acceleration and microstepping maximum speed. hese
settings can be changed and saved into the internal memory of the G 1 using the
configuration software. Illustration 2 shows the graphical layout of the configuration
utility.
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Illustration 2: The pins to short for fail-safe mode

AHP® GT1 Motor Controller - Manual and Usage Guide
Calculation of gear ratios
Gear ratios are calculated using as base unit the gear tooth. Generally telescope
mounts use a crown/worm gear configuration, most of the times they are equipped
with a gear reduction on the motor to the worm. Stepper motors are positional
motors, having a number of steps to complete a 360 degrees turn. he useful fields on
the configuration utility to setup a correct gear ratio are:
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