Jump to content
IGNORED

The "perfect" Lynx....


Level42

Recommended Posts

I tested an iPad charger with a micro USB cable. I measured with one of those USB testers and amps was about 700mA which I expected following my measurements with the Fluke.

 

However although the Lynx worked fine the LEDs were acting strange on the Powerboost. They were lighting up following the music being played ! It looks like a disco ;)

 

Pretty sure it's not getting enough voltage and for now, I blame the micro USB cable which I used. Anyway the new supply I bought doesn't show this behaviour so it already scored points ;)

 

I made short videos which I'll upload a bit later.

Edited by Level42
Link to comment
Share on other sites

In the mean time (have put the Lynx and Powerboost on a duration test) I wanted to solder one of my free LTC2950's to my brand new PCb for it. When I had a look at the bag I got worried....I could barely SEE the LTC2950 !

 

And well.....it's definitely too small for this PCB :(:(

post-25272-0-35002900-1471699594_thumb.jpeg

  • Like 1
Link to comment
Share on other sites

In the mean time (have put the Lynx and Powerboost on a duration test) I wanted to solder one of my free LTC2950's to my brand new PCb for it. When I had a look at the bag I got worried....I could barely SEE the LTC2950 !

 

And well.....it's definitely too small for this PCB :(:(

 

One idea, superglue the chip to the board, and jumper the pins to the pads with some 30 gauge wire.

Link to comment
Share on other sites

 

One idea, superglue the chip to the board, and jumper the pins to the pads with some 30 gauge wire.

 

Haha, well .....man.......maybe you have the skills and eyes to accomplish something like that, but I sure don't !

 

Being an 80's kid I grew up with decent through-hole parts that a human being could handle ! And having classic arcade machines full of that stuff (and some A8 stuff too of course) really spoilt me .......

 

I already was proud that I could remove all that SMD stuff from the Lynx ;)

 

OK so I now learned a bit about SMD types a bit, turns out the LTC2980 is in a TSSOP-8 package and not SOIC-8 (whatever ;))

 

I had already found SOIC-8 boards on Aliexpress that had TSSOP-8 on the other side...regretfully the (much more expensive) one I got doesn't. Also the shop I got everything doesn't have TSSSOP-8, only 28 and that's 20 pins too many (and a lot of board I don't need).

 

Turns out there is a comparable webshop here which is also not far from my home that carries those Aliexpress (like) boards. They indicate it's possible to pick up stuff on arrangement so I'll try that....

 

https://www.hobbyelectronica.nl/product/pcb-voor-soic-8-tssop-8/

 

How I'm going to solder something my son called "smaller than a grain of corn" is beyond me.....I guess I'll need to drag solder. I've seen that on video but never did it myself.....I guess I will superglue the chip first as you say though, there is no other way for sure....

 

Im bummed that I can't complete it now.

 

By the way the Powerboost will ALMOST perfectly fit lined up with the former power connecter.......almost..... There are two coils which are for the Comlynx connection a tiny bit in the way, but I think I'll manage. I might have to enlarge the original hole in the case a little bit.

 

Talking about Comlynx. There is one thing I forgot to list about the "perfect" Lynx: wireless Comlynxing. It's serial right ? so would something like this work ?

 

http://www.dx.com/nl/p/bluetooth-serial-port-module-w-led-indicator-cable-set-blue-white-356891?tc=EUR&gclid=Cj0KEQjw_9-9BRCqpZeZhLeOg68BEiQAOviWAgTWKpsqtZ4no-uQW809oQaSSZ_BjpVV1aqrL6SUEPcaAoYD8P8HAQ#.V7iNvmUT87Q

 

It's not something I am very much in a rush with though....Comlynxing is something I rarely did, but it was a lot of fun for sure when we did (Checkered flag with 5 guys was awesome :D)

 

On the other hand, this whole exercise: at least half the fun is getting this stuff working as we hope...but for now it's not priority nr.1 ;)

Edited by Level42
Link to comment
Share on other sites

Mmmmmmm......now I notice this nice official Raspberry Pi power supply on this Hobbyelectronics.nl website:

 

Voeding_Raspberry_2A.jpg

 

https://www.hobbyelectronica.nl/product/voeding-raspberry-2a-micro-usb/

 

It's 50% cheaper than the one I bought today AND delivers 0,5A more (according to other websites selling this same supply....)

 

So I looked back to the www.kiwi-electronics.nl site because I know they also sell Raspberry Pi stuff and sure enough, they care the same supply at about the same price, but in black.....which fits much better to the Lynx of course....

 

KW-1599-1-1000x667.jpg

 

https://www.kiwi-electronics.nl/raspberry-pi/raspberry-pi-stroomvoorzieningen/rpi-psu-5-1v-2-5a--eu-uk

 

So I guess I'll be trading the supplies, or at least bring one back and get the other one....I want to get that TSSO-8 board but at 0,45 Euro I'm sure the guy isn't going to agree with me picking that up (as his site mentions).

 

One thing I'll also buy from that Hobby-electronicx guy is this:

 

Li-Po_batterij_250mAh_3.7V.jpg

 

https://www.hobbyelectronica.nl/product/li-po-batterij-250mah-3-7v/

 

Smallest Lipo they have and well......I'm just frustrated I can't set-up everything definitely because I'll have to wait for the big lipo to arrive from the Far-East.

This will make it possible to test everything out and mount everything as needed and then simply switch out the battery when it arrives.

Edited by Level42
Link to comment
Share on other sites

Thanks !!!

 

It hurst to have a free Sunday and not being able to finish the job ....everything is still scattered around.....sometimes I get really impatient......I want to re-assemble the cat and play the shit out of it :D :D

 

I guess I'll experiment with the frequency mod a bit......I need to get those resistor values right.....

Link to comment
Share on other sites

My McWill LCD and Lynxman flash cart are on their way, so just waiting impatiently for those right now. Also talking to cowdog about a replacement speaker + zener and mosfet. Once you guys get the battery situation worked out I will be the first test monkey :)

Edited by pixelperfect
  • Like 1
Link to comment
Share on other sites

Those LEDs are indicators of the following:

 

The Red LED indicates when the battery voltage is below 3.2VDC (Low Battery Output)

The Yellow LED indicates when the battery is being charged

The Green LED indicates when the battery is done charging (all full)

 

They're flashing with the music because I think the cable (or the charger, but it's 2A, so in theory that should work) cannot provide enough power for the Lynx plus the music playing on the speaker. It's "on the edge" I think. This makes them trigger I guess....maybe the charger IC is a bit confused.....

 

It could be that the iPad charger cannot deliver the 2A through a standard micro USB cable (where it can through it's own lightning cable), I'm not sure.

 

Anyway, it shows that it's probably best to have a dedicated power supply....with at least 2A output and thick cables, just like Adafruit indicates on their info about the Powerboost 1000C. Remember that this baby can both run the device connected to the +5V output AND charge the lipo battery at the same time...that's a lot of amps needed :)

Edited by Level42
Link to comment
Share on other sites

Yes definitly !!!

 

The Visaton BF-45 I'm using is a 4 Ohms speaker.

 

(http://www.visaton.com/en/industrie/breitband/bf45_4.html)

 

This by itself already means it presents a heavier load to the output of the audio amp (The LM386). However, I bet it's coil and the heavier magnet it has to drive even increases the required power. I think the insane increase in sound quality is very much worth it though :)

 

By the way, I'm pretty sure that the Lynx doesn't have the bass-boost installed on the LM386. The schematics show it as "optional" so in Atari Corp's best tradition it was probably left out to save 1 resistor and 1 cap....well at least I can't find them on the PCB. I'll have to measure if I can find if anything is connected to the LM386 pins for the bass-boost. It would be interesting to try to add it and see how it would sound with the standard speaker. Pretty sure the Lynx II would benefit quite a bit from it !

 

However, with the Visaton I already have excellent bass response and I'd feel the bass-boost would overdo it so I won't bother with it.

 

I was planning to fiddle with the gain control at first because the maximum volume seems a bit lower than with the original speaker (which is as expected) but ......you know......the sound is simply great now and loud enough for any normal use.....why bother ;)

Edited by Level42
Link to comment
Share on other sites

The Lynx II sounds SO much worse than the Lynx I. That's already one of the things why I like the I better.....

 

I did read that Lynx II speakers tend to get bad over time so replacing it might be a good idea for you too.....someone posted links to suitable speakers for the Lynx II. Do a bit of a search here on the Lynx forums...

Link to comment
Share on other sites

Yihaa !!! Could pick up the parts I still needed.....

 

The lipo battery is seriously tiny.....even smaller than the Powerboost......

 

And amazingly it can handle powering the Lynx !!!!

 

Not sure if it can handle the required amps for prolonged times though, but this is just for testing and set-up purposes.....

post-25272-0-73821600-1471960661_thumb.jpeg

  • Like 1
Link to comment
Share on other sites

OK.....so I just learned about the C rating of Lipo's....I found a pretty nice data sheet about this battery and apparently the C value for discharging is 1 max. on this little battery.

 

As far as I understand it that means 250mAH (battery capacity) x C = 250mAH x 1 = 250mA....... oops....the Lynx draws about 700mA at the moment.....yep this means I really will not run it for longer times on the battery.....

Edited by Level42
Link to comment
Share on other sites

Guys I'm really really really excited as EVERYTHING works as envisioned !!!!!!

 

Tonight I managed to solder the fist SMD IC in my life to an already tiny PCB....

 

I first glued the chip to the board which worked....but the thing is so freaking tiny that some glue managed to make it's way under two pins of the chip, but I only noticed that when I started soldering.

 

The first side of the chip actually went pretty easy to solder, all 4 pins were soldered right away and I removed a bit of excess solder with some solder-wick.

 

The other side turned out to have the two pins that had some glue under them. This resulted in the two pins not getting soldered to the board. I used a tiny microscope to check this visually but also could measure it.

 

Now one of the pins I actually didn't need, but the other was GND. So what I did was an old trick which I've perfumed before but not on this tiny scale, but I managed to make a bridge from the pin to the PCB with a tiny bit of wire......

 

Anyway...I wired up the PCB.....connected all the connections as planned and then it was "D-day"....

 

I first only connected the AC power supply. As expected nothing happened so that was the first good sign.

Next I pressed the Power ON button of the Lynx and it fired right up !!!

Let the intro screen come up, pushed the Power ON button again and sure enough it turned off !!!

Exactly as planned :)

 

SO the basic on-off works ! :)

 

Next I connected the tiny test LIPO. As expected the yellow LED for charging turned on.

Then I removed the micro-USB connector from the AC supply. I turned on the Lynx, started the stop-watch and sure enough the Lynx turned off after about 4 minutes, just like it is supposed to do on the Lynx I !!!!! I could immediately power it on again, so it was not the battery going low, it was simply because the Lynx "knew" that AC was not connected ( [AC connected] low ) and following this it activated the Power On signal (which I have inverted through U6), which signaled the LTC2950 to shut down power.

 

SO......I've done it !!! Everything works as planned and hoped right away....which I'm pretty happy with.

 

Again, the ideas for the Adafruit 1000C and the LTC2950 was entirely Cowdog's, but I was happy to make them for real.

 

I made some video but it turned out to be pretty long and my iPhone stopped recording because the memory was full, so I'll make and upload a video a bit later :)

 

Now, everything is still installed with temporary long wires but now I can shorten all the wires and install the PCB's on their permanent spots..... :D

Edited by Level42
Link to comment
Share on other sites

Yes! Awesome news man. I'll have to order up some of those chips to try as well. the STM6601 looks like it does the exact same thing as the LTC2950 at about 1/3rd of the cost.

 

So on the pushbutton, do you have to hold the ON down for a few seconds? Or it it instant off?

 

Definitely want to see your wires on the PCB and schematic so I can translate this to the Lynx II.

 

Also - the easiest way to solder those SMD chips is solder paste and hot air (but you have to have the tools of course). Nice job on the first well documented LiOn Lynx! (Isn't that two animals? lol)

  • Like 1
Link to comment
Share on other sites

Haha LOL, love that Lion Lynx :)

 

Yeah, I figured for this "one time only" SMD soldering I'd use my trusty old Weller. It worked......OK ;) If I hadn't have the glue under the two pins it actually would have looked very decent. It's a bit of a mess visually now, but it's safe and working.

 

Power on is instant.

Power off does not require to hold but it takes about half a second to actually turn off.

 

Here are some pics....

 

First: trying the LTC2950 on the TSSO PCB: fits ! (The other side of this PCB can handle the larger sized chips...)

 

Second: I need a microscope. This tiny one I bought to examine arcade PCB's for cracks works nicely...and was cheap....and has a LED built in :)

 

Third: positioning the LTC2950

 

Fourth.....uhhh....doesn't look fantastic but it works....and I measured everything twice for possible shorts and opens....all fine....

 

 

post-25272-0-26030600-1472075422_thumb.jpg

post-25272-0-60700900-1472075480_thumb.jpg

post-25272-0-75497100-1472075575_thumb.jpg

post-25272-0-11968500-1472075590_thumb.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...