Simp's build log


#1

Intro

I’m a software engineer who has worked in the hardware world for a year. Mainly programming controllers/building integrations to systems etc…

I’ve seen how knowing hardware design can make some projects a lot simpler/cooler/compact. That made me look at different PCB design programs and tutorials online. I found the Hackaday article about Getting to Blinky.

I completed that, but it does take a while for OSHPark to deliver to Europe, so I might need to find a European PCB producer that has good pricing. If anyone has recommendations, I’m all ears.

GTB

I’ve got the board. I haven’t ordered the parts yet, but they are delivered in a day usually. I do have the cart filled already.

Not too worried about the soldering bit. My hand-soldering is ok and i’m thinking of trying to use solder paste and a SMD rework station for this. Should be a perfect little test.

Personal Project goal

My first own project is a LED headlamp hook-up board for a motorcycle. Something that will allow me to dim the lights to use as DRL when needed and shut them down if an indicator turns on. But it’ll take a while before I’m ready to start with that. For now, i’ll solder up GTB and start with the CE header.


#2

Welcome to the forums! To find a PCB house with faster shipping to your area you may like this site: https://pcbshopper.com/. It’ll tell you at least an estimate of how fast you’ll receive your order. There’s also this thread which has a number of reviews you might find useful.


#3

Got the parts for Blinky, didn’t get the solder paste and battery with this delivery, but that’s life :slight_smile:

Decided to go ahead and solder the first one by hand. Almost happy with the result, the capacitor didn’t come out as well as i’d like but it’s ok, especially considering the fact it was my first SMD soldering.


Will go and hunt for a battery tomorrow and see if it’ll work.


#4

That’s perfectly good SMD hand soldering. Congratulations!


#5

Yeah! This is good stuff! Everyone has seen my soldering job, so I’m impressed :smiley:


#6

Ok, so managed to get the battery today. But looks like I haven’t made a blinky. I’ve made a LED light.

The led is always on, not blinking. I took a look at what is going on just before R3, it looks like it’s turning on/off, but way too quickly?

As you can see, i’ve got access to all the tools and none of the competence :slight_smile:


#7

at least you have not given up and have made the first step to see what is going on :slight_smile: The next step would be to ask the question “Why is it switching too quickly?”. Perhaps post your circuit. My understanding of the 555 timer is that the frequency is driven by the RC values. The circuit might help to verify what values you have used.


#8

Ah, yes, of-course. I even made screenshots, but didn’t include them in the post.


So,
R1 = 1K
R3 = 1K
R2 = 470k

That’s exactly what i’ve got on the soldered board as well.


#9

Just in case i’ve made an error when ordering parts. Here are the resistors i’ve got on here:

http://ee.farnell.com/multicomp/mcwr08w4r70ftl/res-thick-film-4r7-1-0-125w-0805/dp/2447677?CMP=i-bf9f-00001000

http://ee.farnell.com/multicomp/mcwr08x1001ftl/res-thick-film-1k-1-0-125w-0805/dp/2446904?CMP=i-bf9f-00001000

Edit: wait, i think the error is in the R2 resistor? 4.7 ohm != 470k. The correct conversion would be 4.7 ohm == 0.0047k ?


#10

Yep, i’m now sure that was the mistake. Took one of the 1K resistors and replaced the 4.7 ohm resistor.

With the same time scale on the scope, i get longer periods. Still not enough to see it blinking, but i think it confirms the source of the problem.


#11

Well done! So… what were you saying about competence?


#12

Well I still need to start understanding the datasheet and figure out the correct values from there :slight_smile:

As usual, all one needs is a little nudge in the correct direction. Thank you Steve for that nudge.

and here’s an ugly fix, found a 330k resistor and gave it a shot.



#13

From my perspective of Contextual Electronics is that a Bodge on a working board is just proof that something was learned. …and yes, I have had to bodge a few boards :slight_smile:


#14

Excellent job debugging! I like your persistence in tackling the problem. That’s a great skill to have.