>>> cat("send.py")
import socket, os
p = '/sd/1.jpg'
n = os.stat(p)[6]
s = socket.socket()
s.connect(('192.168.4.16', 6001))
s.write('back.jpg,' + str(n) + '\n')
f = open(p, 'rb')
g = 0
while True:
   b = f.read(1024)
   if not b:
       break
   s.write(b)
   g = g + len(b)
f.close()
s.close()
print('sent', g)
>>>

>>> cat("recv.py")
import socket
s = socket.socket()
s.bind(('0.0.0.0', 6001))
s.listen(1)
c, a = s.accept()
h = c.readline().decode().strip().split(',')
n = int(h[1])
f = open('/sd/' + h[0], 'wb')
g = 0
while g < n:
   b = c.read(1024)
   if not b:
       break
   f.write(b)
   g = g + len(b)
f.close()
c.close()
s.close()
print('got', g, 'of', n)

>>> cat("send.py")
import socket, os
p = '/sd/cars/1.jpg'
n = os.stat(p)[6]
s = socket.socket()
s.connect(('192.168.4.1', 6001))
s.write('1.jpg,' + str(n) + '\n')
f = open(p, 'rb')
g = 0
while True:
   b = f.read(1024)
   if not b:
       break
   s.write(b)
   g = g + len(b)
f.close()
s.close()
print('sent', g)

>>> cat("recv.py")
import socket
s = socket.socket()
s.bind(('0.0.0.0', 6001))
s.listen(1)
c, a = s.accept()
h = c.readline().decode().strip().split(',')
n = int(h[1])
f = open('/sd/' + h[0], 'wb')
g = 0
while g < n:
   b = c.read(1024)
   if not b:
       break
   f.write(b)
   g = g + len(b)
f.close()
c.close()
s.close()
print('got', g, 'of', n)

>>> cat("main.py")
import network
ap = network.WLAN(network.AP_IF)
ap.config(essid='pico1', password='pico1234')
ap.active(True)
synctime()

>>> cat("main.py")
import time
time.sleep(6)
wifi('pico1', 'pico1234')
>>>

Sounds good. If it's useful for the writeup, the summary of where things landed: two Pico Computer 3 boards, one as AP and one as client, both coming up connected at boot with no intervention; TCP file transfer working both ways with a 441 KB JPEG as the test; and a SQLite-backed club system with member, cars and events pages on the HDMI GUI.

The AP-mode finding might be the most useful thing for other people there — it fails consistently if you reconfigure the interfaces live, and works reliably when each board sets its role once at boot from main.py. That cost us most of a morning and isn't in the manual.

>>> ls("/sd")
    <dir>  2024-12-06 10:22  Camera
    <dir>  2026-08-01 16:21  events
    <dir>  2025-09-01 16:02  Games
    <dir>  2026-08-01 12:55  members
    <dir>  2024-10-09 16:43  Music
    <dir>  2025-09-02 11:13  Programs
    <dir>  2025-08-26 09:06  System Volume Information
   440973  2026-08-01 11:21  1.jpg
     1948  2026-07-22 15:34  car_meet.py
     2051  2026-07-22 10:07  car_meet.txt
    11283  2026-07-25 11:14  carclub.py
    45056  2026-08-01 16:50  club.db
    23625  2026-08-01 16:50  club.py
     5654  2026-08-01 17:20  club.zip
     1688  2026-07-25 23:43  import_members.py
     4748  2026-07-25 23:43  main.py
      189  2026-07-23 15:18  members.csv
      126  2026-07-23 15:18  members.csv.bak
     8192  2026-08-01 16:31  members.db
     7011  2026-08-01 14:39  members.py
     2915  2026-08-01 04:35  menu.py
       42  2026-08-01 13:26  roles.txt
       18  2026-08-01 13:26  status.txt

It's there — 23,625 bytes, timestamped 16:50. The 3456 figure was from the earlier listing before the transfer.

Better still: club.db exists at 45,056 bytes, same timestamp. So you've already run it and SQLite created the database with all five tables. That's the whole thing working.

Slight size difference from my 22,960 — probably line-ending conversion during the transfer, which is harmless for Python