Connect Thunderborg (LID) Controller to Raspi 3 with cables

Hi,

on your web site https://www.piborg.org/blog/build/thunderborg-build/thunderborg-getting-... I see, that the controller will be connected to the raspi gpio pins 1-6 (5V 5V Grd and 3V SDA SCL. My Question am I right, that the controller needs all the gpios? I plan to use the raspi sensehat which conflicts with some gpios used by the controller.

kind regards

Peter

piborg's picture

The ThunderBorg does use all of these connections, but it should be able to share them with the sense hat :)

Basically SDA and SCL are special pins used for a type of connection called I2C. This works by sending messages with an address at the start. As long as the address used by the ThunderBorg and address(es) used by the sense hat are different they can both be connected to these pins at the same time.

Hi,

many thx I'm aware about i2c bus. Thats not the problem. Additionally I use 2 SFR08 ultrasonic sensors with need 5 volt. So I built my on level shifter board using a bi directional level 3V / 5 V in combination with a step downconverter. So I can solve the power and i2c problem. My question now. is it posssible to connect the 12 volt battery block to the step step down converter. Connect the 5 volt output with my level shifter board an then use the 5 V side to connect to your motor controller?
Or do you have another idea for another soultion how to connect your motor controler, 2 SFR08 and the sensehat via one battery pack? Normally I like using a raspi 3 and not the zero for this kind of project.
Many thx in advance

kind regards

Peter

piborg's picture

There is actually a simpler solution, do not connect 5V to the ThunderBorg at all :)

The ThunderBorg's on-board DC/DC will provide 5V to the board from the battery connection. It will still need the 3V3 and GND connections to power some of the logic correctly.

Hi,

thx for your reply, don't really understand, what you mean with simpler soultion. Could you please go little bit more in detail, where I can connect my 5 Volt sensors? many thx

Peter

piborg's picture

I think I have misunderstood what you are trying to do.

Could you draw a quick diagram of the parts you are trying to connect up?

Hi,

here it is :-)

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piborg's picture

What are the four connections from the 3V side of the level shifter supposed to connect to?

I was expecting them to be 3V3, GND, SCL and SDA, but you have one labelled 5?

Hi,

the cabling is as follows:

3V side level shifter: SDA (line 2 LS from above) to PIN3 SDA sensehat
3V side level shifter: SCL (line 3 LS from above) to PIN5 SCL sensehat
3V side level shifter: 3V (line 1 LS from above) to PIN17 3V raspi
3V side level shifter: Ground (line 4 LS from above) to PIN9 GND raspi

3 and 5 on the LS means to pin 3 repsective to pin 5 on sensehat. Sorry please check my diagram. I tried to make things more clear.

kindly

Peter

piborg's picture

In that case you should be able to connect the ThunderBorg as follows:

  • 3V3 to the 3V side of the level shifter
  • GND to the 3V side of the level shifter
  • SCL to the 3V side of the level shifter
  • SDA to the 3V side of the level shifter
  • Leave the 5V pins disconnected

This will mean that the DC/DC on the ThunderBorg will only power the on-board logic, the step down converter will power 5V everywhere else. This should be fine as long as the step down converter has a high enough current limit for the devices in your diagram and anything else connected to the Pi's USB ports.

many thx, one further question on your shop side, you show a diddy borg with 4 SFRs and a servo for a robot arm. How do handle here the i2c and power issues. Is there an extended building instruction for the example with SFR sensors and server (or at least a cabling plan with part-list) Would be great.

regardly

Peter

piborg's picture

For the DiddyBorg in that example we use an UltraBorg to control the servos and read the ultrasonic sensors. UltraBorg is designed to use HC-SR04 sensors which are not I2C, instead they have signal lines which need to be timed. The servos directly plug in to the UltraBorg and the ultrasonics are each connected with a 4-pin cable.

The 5V power for the servos and sensors does not have to be as precise as the supply for the Raspberry Pi, so we usually suggest using a UBEC to supply their power separate from the Pi's 5V supply. This is connected to the UltraBorg which handles the necessary voltage changes.

Thx for your explanation, so if using UltraBorg and your HC-SR04 sensor I would get the distances of 2 or 4 HC-SR04. So I could decide how to control my motors. I think, I have no problem to give the UltraBorg a separated batterie pack. But after some investigating on the ultraborg (https://www.piborg.org/blog/ultraborg-getting-started) stuff, I see that Ultraborg exactly need the same Raspi Pins 1-6 as the Thunderborg. So how to connect the your ThunderBorg Controller to the Raspi?

regardly

Peter

piborg's picture

The ThunderBorg and UltraBorg are designed so that they can be daisy-chained together, allowing them to be connected to the same Raspberry Pi.

This is done by connecting one of the boards directly to the Raspberry Pi, then connect the second board to the Daisy-chain connector on the first board.

Hi,

cool many thx.

Hi,

just working on my robot. One question refering of the cabling of the boards. Does this work?
Many thx in advance.

Peter

piborg's picture

The connections look right. The 12 V battery should be connected to the ThunderBorg.

It is hard to tell how exactly the wires are connected between the UltraBorg and the ThunderBorg in your diagram. Here are the pin connections on the ThunderBorg :

DO NOT connect the 12V battery to the UltraBorg! The battery connection on the UltraBorg is only for a 5V supply for any servos / ultrasonics connected to the board:

  • If you are using servos disconnect the 5V link jumper and add a 5V supply / battery pack to the UltraBorg
  • If you are only using ultrasonics leave the 5V link jumper on and do not connect anything to V+ and GND

Hi,

many thx, cool ....

regardly

Peter

Hi,

I see your point and after investigating your manuals a see a mismatch. I one picture the thinderborg is connected to the raspi using the male connector pod.
https://www.piborg.org/blog/build/diddyborg-v2-build/diddyborg-v2-build-...
In thunderborg daisy chaining example it is connected to the female connector pod?
https://www.piborg.org/blog/build/thunderborg-build/thunderborg-getting-...

I hope, I did a more clear drawing. Please check if I'm right or feel free to correct it.
Many thx and happy easter

Peter

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piborg's picture

That all looks correct to me :)

Happy Easter.

Hi,

after finalising cabling. One motor starts later than the other 3 and after starting it seem to be slower than die other motors? I checked cabling, removed ultraborg and sense (only raspi and thunderborg) see no improvement. Using a python script from my monsterborg, where it worked perfect, all 4 motors)
Second, i2cdetect sees my thundorg i2c on 15 and the complete sensehat ic2 numbers, but ultrabog in between it, is not recoginzed (I2c bus 1, missing address 36).
Any ideas?

many thx

regardly

Peter

piborg's picture

The UltraBorg issue could be a fault with the board itself. Could you try connecting it by itself to the Raspberry Pi GPIO using the 3-pin cables and try i2cdetect -y 1 again to see if anything shows up.

As for the motor speed it could be a slow motor. Can you try just the problem motor on one output and one of the other motors on the other output to see if the behaviour changes.

Hi,

I connected the ultraboard to the another raspi. Some behavior i2cdetect -y 1 shows nothing :-)? Some with the motor, connecting only a right an left one. Same behavior it starts later an slower :-)

regardly

Peter

piborg's picture

We have been doing some investigation and it seems a small number of UltraBorgs were sent out unprogrammed by mistake :(

If you could send our sales team a message using our contact form explaining the problem they will get a replacement motor and UltraBorg sorted out for you. Choose "Direct contact" and include your order number :)

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