[0:00] it’s time for a bit more testing of the
[0:01] boards from PCB way I must say these
[0:04] boards have come out amazingly well
[0:06] check out PCB way there is a link in the
[0:08] description of the video and thanks also
[0:09] to all the patreons who are supporting
[0:11] me so what I want to test today is the
[0:14] battery charging and the expansion Port
[0:16] so I plugged in the battery you can see
[0:17] it’s at 4.1 volts and we’re testing out
[0:20] the charging circuitry and I have messed
[0:22] this up before so I’m quite interested
[0:24] to make sure that I’ve done it right so
[0:26] hopefully we should see the battery
[0:27] voltage going up so that seems to be
[0:30] pretty successful we also want to
[0:32] monitor how much current we’re drawing
[0:34] so 200 milliamps with the whole thing
[0:36] turned off that does match up with the
[0:38] actual resistor I’ve used for the um for
[0:41] the battery charging circuit and then
[0:43] when we’re running we’re running at
[0:44] around 300 milliamps so that’s not too
[0:46] bad what’s quite interesting when
[0:48] there’s music playing is um it is
[0:50] actually drawing quite a lot of C so
[0:52] around 4.5 amps and if we look at the uh
[0:55] the graph it’s really fascinating so we
[0:58] are drawing quite a lot of current with
[1:00] the speaker and the voltage which is the
[1:02] yellow Trace is dipping down quite a bit
[1:05] so you can see that if I just um move
[1:07] this a bit closer When the Music Stops
[1:08] it calms down a bit but then as soon as
[1:10] we start playing music again we do get
[1:13] that voltage drop and the current spikes
[1:15] so I think what I need to do is add a
[1:17] bit more decoupling capacitors around
[1:19] the speaker side of the system um so
[1:21] I’ll be looking at that and how to
[1:23] improve
[1:27] that and if we turn off then uh
[1:29] everything goes back just to charging
[1:31] the battery um so we’re back to our 200
[1:34] milliamps now I may actually increase
[1:36] the charging current uh with a 1,000
[1:39] Milah battery that’s going to take a
[1:40] while to charge but just to prove it
[1:42] does work I’ve just unplugged the USB
[1:45] and you can see it’s all running off
[1:46] battery now so everything works as you’d
[1:48] expect and we still can play Manic minor
[1:51] so that’s pretty good we still get all
[1:53] the stuff working and it works really
[1:55] well off battery that’s not bad at all
[1:57] and just to check I’m going to try
[1:59] charging the battery to its full
[2:00] capacity so just to prove it is working
[2:03] you can see the light has turned green
[2:05] when the battery is fully charged now
[2:07] you might be wondering what all these
[2:09] wires are doing here well I want you to
[2:11] test the expansion Port as well so what
[2:15] I’ve done is I’ve exposed the display
[2:17] lines on the expansion port and I should
[2:20] have exposed the SD card pins on the
[2:22] expansion Port but unfortunately I made
[2:25] a slight wiring mistake and I didn’t
[2:26] expose the right pins but what I’ve got
[2:29] now is a p Pico my nice pink P Pico
[2:34] wired up to the expansion port and the
[2:37] display so what we should be able to do
[2:39] now is let me just move the camera so
[2:42] you can see everything um I’ll plug in
[2:45] the p
[2:46] peo and turn on the
[2:49] board plug in the
[2:51] PPO we’re now running an emulator on the
[2:54] PPO which is driving the display via the
[2:57] expansion port and it’s hooked up to my
[3:00] keyboard so what we should be able to do
[3:03] if this is
[3:05] working let’s just uh make sure
[3:08] keyboard’s
[3:10] configured and why is it now working oh
[3:13] there we go so there we go so this is
[3:16] working over I squ C so our esp32 is
[3:19] reading the keyboard and that’s sending
[3:21] messages over I squ C to the Pico which
[3:24] is running another emulator that’s then
[3:26] driving the screen so you can see that
[3:28] all works nicely we can go into basic
[3:31] and I’ve also hooked up the buzzer so we
[3:34] should be able to get a beep out of
[3:37] this so beep one comma
[3:41] 2 it’s pretty quiet but if we go into
[3:44] the menu which I think I do like that
[3:47] get a nine and then Pump Up the
[3:52] Volume and then exit from that let’s try
[3:55] that
[3:57] again peep one comma
[4:01] two we’ve got sound as well now I’m
[4:05] going to jewelry rig the SD card so that
[4:09] I’m exposing the right pin and try that
[4:12] and then I’ll show you something quite
[4:13] interesting so I’ve got my bodge wire
[4:16] wired up and um now I’ve got everything
[4:18] else wired through the expansion Port so
[4:21] if we go into the menu go into snapshots
[4:23] you can see we have all these snapshots
[4:26] and that works well so let’s scroll down
[4:29] and we’ll start up the usual manic
[4:35] minor so that’s working fine loads it
[4:39] up going to jump around oops de it so
[4:44] why is this interesting you might ask I
[4:45] mean we can do this with the esp32
[4:48] what’s so special about this expansion
[4:50] slot well let me show you something very
[4:52] cool so yes why is this interesting well
[4:56] I’ve now wired up an HDMI Breakout
[4:59] boorder
[5:00] still plugged into my keyboard here but
[5:02] if I turn the camera
[5:04] around there you go we have a big screen
[5:08] everyone’s been asking for it you’ve now
[5:10] got one so this is all very experimental
[5:14] obviously at some point we’ll need to
[5:16] make this work properly uh with an
[5:18] expansion um board but um yeah it’s
[5:21] pretty good so let’s just type in a bit
[5:23] of code hello world
[5:30] where’s the semicolon G there it
[5:41] is there we go big screen for you all so
[5:45] um obviously what we need to do is get
[5:47] this board actually finished on in
[5:49] production so the expansion board will
[5:51] come later I need to start thinking
[5:54] quite carefully about um Emi and EMC so
[5:58] I’m going to spin up a new version of
[5:59] the board I’ll be switching to a four
[6:01] layer board and I’m thinking about those
[6:03] sort of things now getting ready for
[6:05] production so I’ll see you in the next
[6:08] video