Shruthi 1 doesn't boot [solved]

hello pichenettes I have just soldered the 2 PCBs and when booting up, the LCD doesn’t display anything even if we see red light on the 2 sides of the LCD module. And neither the LED 3 and 7 are on, just the LED 8, and nothing reacts to user actions.

> salut pichenette, j ai fini de souder les 2 PCB mais à la mise en route, l’écran LCD n’affiche rien alors qu’on voit de la lumière rouge sortir des 2 cotés latéraux .Et ni la led3 et7 ne s’allument ,j’ai uniquement la led 8 qui s’allume et ni l’encodeur ni les boutons ne réagissent à une action

At which step are you? 11 or 12? If you are at step 11, and are just testing the LCD without it being soldered, it’s quite normal to see something wrong on the LCD. If you are at steps 12, did the LEDs/encoder worked at step 11 before you soldered the LCD?

Now we have to find out why it doesn’t seem to boot up… A few things to check:

  • The solder joints of the quartz and capacitors near the quartz
  • The ATMega644p is correctly inserted (right orientation, no broken pin)

And a note: maybe when there will be 1000s of Shruthi out there it will make sense to have one forum per language, but at the moment, it’s more likely that someone will help you, and that someone will find help by reading this discussion if it is in english - even if it is google translate english…

> Tu en es à quelle étape ? La vérification des LEDs se fait à l’étape 11 quand le LCD n’est pas en place. Tu en es à cette étape là ? Ou ça s’allumait comme il faut avant que tu mettes le LCD, mais plus maintenant que le LCD a été inséré ? Pour le contraste de l’écran, il faut essayer d’ajuster le trimmer. Même quand le processeur est enlevé ou que la carte est kaput, il doit afficher la première ligne “pleine”. Essaie de le tourner à fond dans un sens, et si ça ne marche pas, à fond dans l’autre sens.

Pour les LEDs qui ne s’allument pas :

  • vérifier les soudures du quartz et des deux condensateurs autour
  • vérifier que l’ATMega644p est correctement inséré (pas de pattes pliées sur le côté) et dans la bonne orientation

Dernier point : quand il y aura des milliers de Shruthi dans la nature on pourra mettre un forum spécifiquement en Français, mais avec un message en anglais il y a bien plus de chance que ça fasse réagir quelqu’un qui a eu le même problème, ou que ça serve plus tard à quelqu’un qui a le même problème.

pour l’écran,c’est ok, j’ai 2 lignes pleines (trimmer mal reglé)

par contre ,j’ai soudé l’écran sans vérifier les led.
les soudures du quartz et des condensateurs ont l’air bonnes mais comment être sûr ?

C’est bizarre d’avoir les deux lignes pleines… Quand on baisse le contraste progressivement on ne voit pas la splash screen “mutable instruments” s’afficher ?

non, j’ai 2 lignes de rectangles rouges

I’m haivng the same issue, LED 8 is only thing working at step 11.

I noticed there is a discrepancy between the parts list and the step by step instructions for IC 2 and IC 3, which are soldered directly to the pcb

From Parts listing:

IC2 74hc165 shift register
IC3 74hc595 shift register

in the step by step instructions:

"Step 7… Insert and solder the following components:

1. IC2 and IC3 (74hc595 and 74hc165). Orientation is important. The notch should be on the top."

I followed the instructions and now have to desolder or cut out the chips and buy new and resolder in their correct locations. Not a fun start to the project. Has anybody found any other errors/typos in the assembly instructions for the other boards?


Yes this sentence is ambiguous and could you make you think that IC2 is a 595 and IC3 a 165. But then this disagrees with: the BOM ; the marking on the PCB ; the schematics and the assembly photo (the chips in the kits were like those on the photo).

Ok, I had a doubt reading this thread so I checked my digital board and I realized that I’ve inverted IC2 and IC3… but my shruthi works with no problems (at least for what I can say!)

So my question is: what the two IC are used for? Just to undertand why my mistake doesn’t affect my shruthi (again… for what I can say)…

Hell, don’t you guys read whats on the PCB or look at the PICs (or as my Dad always told me:“First think, then solder else socket.”)?

According to the Datasheets (74HC595 74HC165) the funtion and the pinning is quite different.

A look to the schematics shows the 595 is a serial in > parallel out shift register that drives all your LEDs from one single signal line from the ATMega, the 165 is the oposite, its a parallel in> serial out shift register which is used to read all the buttons with one single line from the ATMega. If you scramble them up the LEDs wont be lit correctly and there will be no response to the Buttons. In case you swapped IC2 and IC3 the 8th LED is lit because its connectet to (NOT)Q7 of the 165 which is the inverted output of the status of last stage D7 which in this case is connected to LED 7 (open) so it indicates that “nothing” is connected to Pin 6.

So its a real Miracle Muldee

P.S.: In the German Language a listing of things does not indicate a location until this is explicitely mentioned. I would never had that idea, but the Instructions should be changed here to be clear to the bones, although its not a typo/error/mistake as harlen pointed out.

@fcd82: never mind… probably I was still sleeping while I was reading the forum this morning. Not swapped the ICs, no miracle, only me writing stupid things on this thread… sorry.

Hey Muldee,

thanks for makin me 10 years younger, what do you want to drink? :wink:

A big mug of beer to celebrate the fact that I do not have to exorcise my Shruthi-1, thanx :smiley:

salut, tu l’as bien reçu car avec la Poste…

I have received frelou’s board and as guessed by fcd72, the two ICs were swapped.

Yeah Baby! Im the Hardwaremaster :wink:

Sincerely, glad it was that simple!

was this wrong in the documentation? the printout I have has them reversed in the BOM

The Ic’s names were inverted in the assembly instructions, now they are correct.

To be clear: The BOM, the Pics and the print on the PCB were correct, in the assembly instructions the ICs were mentioned in a way that if you insist that the first element in a row must be oriented as the leftmost might make you think the 165 goes to the left slot. But you then would have to ignore the BOM, the Pics an most important the Print on the PCB right under your fingers where you put your chip (i was tempted do mention the schematics but i have the feeling most people ignore them…). Blaming the author for beeing able to ignore all this is ridicoulous.

Just another last time to clarify:


Once I’m back home, I’ll do an export of the gerbers seen from top and seen from bottom to make this ultra-clear. Beyond this point, I don’t see much besides selling PCBs with the 74hc… already soldered in.

Maybe you could ask Nathanaëlle for soldering all the PCBs…