"They also build that do not work with wood" - Trampa: Self build MIDI footswitch.

[SamIAm]

For those interested, Trampa in its current form draws a fairly steady 160mA.

 

The battery in the pedalboard has a capacity of 10,000 mAh, which should give an operating time between charges of about 62 hours! 🎉

 

Once I get the extra 3 displays in, this will reduce ... worst case to about 15 hours ... tho it is possible to do some clever stuff with low power consumption with the cpu so might be better.

 

S'manth x

[Richard R]

15 hours should do you. Unless you're playing the entire festival.

[SamIAm]

6 minutes ago, Richard R said:

15 hours should do you. Unless you're playing the entire festival.

Indeed!  And 10,000 mAh capacity is not that large.  I do have plans to build some widgetry so I can also power my Ant amp and HX Stomp using from the USB power bank (or a larger cousin) to be totally mains free; I play in a ukulele band, my band mates can go totally acoustic for street based or other "venues" where we have no access to power ... I could with my Roland Microcube (10h with a fresh set of rechargeable AA batteries), but my current setup needs more juice.

 

S'manth x

[FinnDave]

The Grateful Dead cover band I play has often rehearsed (and played to audiences) in fields using battery inverters and regular amplifiers. I don't know the details of the equipment used (I just plug in) but i could find out easily enough. I bought my TE Elf primary because it works perfectly when powered by a 12v battery and inverter.

[tauzero]

I think the current draw of an HX Stomp is around 1A @9V, so just running off a 10000 mAh 5V USB bank should give about 5 hours of use.

 

 

Step-up voltage regulators seem pretty cheap and you'd only need a 2A capable one. I've only used step-downs so far. One thing I do prefer is fixed voltage ones rather than adjusting the voltage with a pot, which is probably a silly preference.

 

Have you any plans to publish the plans and software?

 

Incidentally, I do love the ESP32 but I feel guilty about not using all its capabilities. I built a footswitch for page turning (and line up/down) using an ESP32 for BLE, and it's a pretty simple little thing.

[SamIAm]

3 hours ago, tauzero said:

I think the current draw of an HX Stomp is around 1A @9V, so just running off a 10000 mAh 5V USB bank should give about 5 hours of use.

 

 

Step-up voltage regulators seem pretty cheap and you'd only need a 2A capable one. I've only used step-downs so far. One thing I do prefer is fixed voltage ones rather than adjusting the voltage with a pot, which is probably a silly preference.

 

Have you any plans to publish the plans and software?

 

Incidentally, I do love the ESP32 but I feel guilty about not using all its capabilities. I built a footswitch for page turning (and line up/down) using an ESP32 for BLE, and it's a pretty simple little thing.

Cool video!

I also want to try to power my Ant Amp from the same battery, but I have a 20,000 lying about ... the Ant has a mains power input only and I've not yet had any success getting hold of the schematic for it yet.

 

I was thinking to build a wee intelligent widget for the Stomp, to use the Quickcharge protocol to request exactly what it wants ... but I've not done that yet, I did buy a handful of cheap power boosters (80 pence each) which claim (and reviews backup) can boost, tho they do look a lot like Buck converters!  I must try one to see if I can run the Stomp.

 

And ... oh yes I hear you ... the ESP32 for this purpose is like using a Land Rover Defender to drive down the road to the shops ... but they are fairly cheap and have the WiFi and BLE built in.  Also, as I was researching how to build the Tramps I stumbled across the PedalinoMini and it seemed rude not to use it! lol

 

I shared some changes I'd made to the source code as well as STLs for the enclosure back at the Pedalino github site [https://github.com/alf45tar/PedalinoMini/issues/342] (I did the design in Fusion 360, if you want a copy of that file drop me a PM); when (if!?) I get around to adding the extra 3 OLEDs and modifying the code, I'll be submitting a PR.  My only challenge is that I've got a Pi/Synth type pedal project simmering and am in full on design mode for a 5 string multi-short-scale bass that is chewing up my time ... and I still have a long way to go in understanding how to effectively use the Stomp, I've only got some very simple patches configured so far; still it all keeps me out of getting into too much trouble elsewhere lol

 

S'manth x

Edited June 9, 2022 by Smanth

[tauzero]

I recently put a Zynthian together and also have another Pi 4 powered softsynth playing SF2 via Fluidsynth - https://github.com/albedozero/fluidpatcher but I've modified mine to use a 20x4 character display.

 

The approach I've taken to powering ESP32 and Raspberry Pi things is to just use a 9V 5.5/2.1 DC socket with a bridge rectifier to avoid embarrassing reverse polarity catastrophe and buck converters set to 5V running to Vin. For Arduinos I also use a bridge rectifier but I just put the 7.5V from the bridge rectifier into Vin. That means not using any USB connectors for powering devices (Zynthian is an exception to this, but I had no say about the means of powering it - a headless Zynthian I've made, if I bother boxing it up, will be 9V powered).

 

Looking back at the pictures of your mockup, I see Squishbox is in there so you may already have got to Fluidpatcher, it supersedes Squishbox.

Edited June 9, 2022 by tauzero
Added bit about Squishbox

[SamIAm]

6 hours ago, tauzero said:

I recently put a Zynthian together and also have another Pi 4 powered softsynth playing SF2 via Fluidsynth - https://github.com/albedozero/fluidpatcher but I've modified mine to use a 20x4 character display.

 

The approach I've taken to powering ESP32 and Raspberry Pi things is to just use a 9V 5.5/2.1 DC socket with a bridge rectifier to avoid embarrassing reverse polarity catastrophe and buck converters set to 5V running to Vin. For Arduinos I also use a bridge rectifier but I just put the 7.5V from the bridge rectifier into Vin. That means not using any USB connectors for powering devices (Zynthian is an exception to this, but I had no say about the means of powering it - a headless Zynthian I've made, if I bother boxing it up, will be 9V powered).

 

Looking back at the pictures of your mockup, I see Squishbox is in there so you may already have got to Fluidpatcher, it supersedes Squishbox.

Were we separated at birth!? lol

It sounds like you've some great fun, what's your pedalboard like these days?

 

I've a R4 Pi with a HiFiBerry DAC+ADC Pro hat on it.

I've tried Zynthian, Squishbox, Modep/Patchbox ... the treefallsound pi-Stomp Core is the one I'd really like to get running but it's all been a massive fail so far  mt32-pi looks cool too! and I really fancy having a play with sonic-pi.

 

But I just can't get any sound out of my HiFiBerry; Jack fails to start ... my knowledge of Jack/ALSA/etc is 0.5/10 at most which doesn't help.  I've gone back to basics and am playing with HIFIBERRYOS just to make sure my HiFiBerry is actually working ... but I've yet to have any success (I think I've a cheap I2S audio card in my ESP32 starter kit I could repurpose).  I've a box of 1/4 jacks, push-rotary encoders, pretty LEDs etc all set to go but ... but other projects are taking up more of my attention; I guess I just need to focus!  So much fun to be had.

 

I also have a "vision" (Cue inspiring music) of combing various elements into a single box and wrapping them all in a nice uniform html5 UI (Playing with masonite and FastAPI).  I stumbled over this the other week and really fancy implementing a web based HX edit type tool using this kind of approach ... it would also allow really tight integration between a Trampa type scribble strip foot controller with my Stomp.

 

S'manth x

[tauzero]

My pedalboard is intended to hold HX Stomp, expression pedal, 6-button MIDI controller, Line 6 G50 wireless receiver, mini mixer, and Fluidpatcher (successor to Squishbox) with a McMillen 12-step to control it, and a power supply of some sort. However, I'm no longer with the bands I was going to use it with, and I hadn't quite sorted out the power supply (HX Stomp and a Raspberry Pi 4 suck up a fair bit of power between them) - I've got a few buck converters which I was going to string together and run from a 12V laptop power supply, must get round to trying that sometime.

[SamIAm]

33 minutes ago, tauzero said:

My pedalboard is intended to hold HX Stomp, expression pedal, 6-button MIDI controller, Line 6 G50 wireless receiver, mini mixer, and Fluidpatcher (successor to Squishbox) with a McMillen 12-step to control it, and a power supply of some sort. However, I'm no longer with the bands I was going to use it with, and I hadn't quite sorted out the power supply (HX Stomp and a Raspberry Pi 4 suck up a fair bit of power between them) - I've got a few buck converters which I was going to string together and run from a 12V laptop power supply, must get round to trying that sometime.

Very nice!

 

I'm aiming for a similar but smaller setup.

A synth of some sort will fit in top right; I'll move power to below the pedalboard and have a floating expression pedal.

 

I just wired up on of my booster circuits to the Stomp.

It did power the stomp from a 5v USB input, the Stomp was drawing apx 800mA@9v (Much as the video you posted suggested) but it was pulling 2.3A (yes 2300mA)@5v from the USB ... not gonna cut mustard for me.  I'm searching down the USB PD approach to see if it is any more efficient.

 

And on an ESP note, my eyes bugged out a little when I saw this beauty!

£6 from the Pi Hut!

No idea what I need it for but I want one! lol

 

S'manth x

Edited June 10, 2022 by Smanth

[tauzero]

4 hours ago, Smanth said:

I just wired up on of my booster circuits to the Stomp.

It did power the stomp from a 5v USB input, the Stomp was drawing apx 800mA@9v (Much as the video you posted suggested) but it was pulling 2.3A (yes 2300mA)@5v from the USB ... not gonna cut mustard for me.  I'm searching down the USB PD approach to see if it is any more efficient.

 

That 2.3A looks well over the top - how can the converter survive dissipating that much power, assuming it has to be dissipated? I know it's just 4W or so but these aren't big components.

 

My approach has been that I'm going to be running a wired connection from the pedalboard to the amp, and a mains connection to the amp, so I'm happy to run a mains wall-wart to a DC extension cable which I cable-tie to the jack-jack lead from pedalboard to amp and feed that into the power supply.

 

Not sure about that C3 Mate, you seem to lose a load of pins and the Bluetooth/BLE side of things compared to the WROOM or others which are £6-£6-50. It is an instant IWOOT but a little consideration is justified before buying it (says the man with three RP2040s, one of which seems to have disappeared).

[SamIAm]

6 hours ago, tauzero said:

 

That 2.3A looks well over the top - how can the converter survive dissipating that much power, assuming it has to be dissipated? I know it's just 4W or so but these aren't big components.

Not sure, I only ran it for about 30s at which point I started to wonder if I should break out some eggs to fry lol

 

I've not played with an RP2040 per se, but I did assemble a tone generator using a pico ... nice little unit.

 

But the dark side of integrated wireless calls to me ... and I was powerless to resist.

 

So a couple (cause I always blow one up!) of the C3 mates are coming my way. 😊 

[nekomatic]

Hello, my name is nekomatic and I also have a collection of microcontroller boards that I bought because they sounded cool but have never done anything with 😄

Fortunately I don’t have anything MIDI controllable so this thread hasn’t had me ordering any new ones - yet. 

Nice project tho!